A revelatory early scene in Raoul Peck’s recent historical film, The Young Karl Marx, depicts the also young Friedrich Engels visiting his father’s factory in Manchester. Friedrich Engels Sr. is attempting to identify the culprit for a recent act of industrial sabotage when a fiery, red-haired cailín steps forward and ostentatiously assails the wealthy industrialist for his callousness. Engels Sr., in language that confirms his status as a gouging capitalist, reminds her that ‘You’re lucky I don’t sack the lot of you! Repairing machines is expensive, not like labour in Manchester.’ The militant female Irish worker then duly identifies herself: ‘My name is Mary Burns. I was born in Tipperary, and am now a slave at the Ermen and Engels Spinning Mill in Manchester, England.’ Soon after, Engels Jr., already nursing grievances against his conservative pietist father, seeks out Burns in the Irish slums of Manchester and thereafter begins an affair with her.
Fig. 1: “Mary Burns” (Hannah Steele) and “Friedrich Engels” (Stefan Konarske) in The Young Karl Marx (2017)
The image imparted of Burns is an undeniably appealing one; a fierce Irish proletarian, uncowed in the face of her capitalist employer. And her encounter with Engels Jr. becomes a sort of origin-story for his studies of Irish migrant labourers in The Conditions of the Working Class in England. Unsurprisingly, there are also some major problems with this image. Mary Burns was not born in Tipperary, or indeed anywhere in Ireland; she was born in England. There is no evidence that she ever worked at Ermen and Engels, the cotton mill in which Friedrich Engels Sr. held a partnership share (and at which Engels Jr. would work, with intermissions, for almost thirty years). How and when Engels first met her is unknown. And it is unclear what, if any, were her political or intellectual influences on the father of Scientific Socialism.
This article seeks to recover, as much as is historiographically possible, the life story of both Mary Burns (1821-1863) and of her younger sister, Lydia “Lizzie” Burns (1827-1878), who also had a romantic relationship with Friedrich Engels and formally married Engels just before her death. The history of women, like those of the working classes and racial minorities, is always bedeviled by what EP Thompson famously called ‘the enormous condescension of posterity’, in which illiterate peoples are erased from the historical record. Yet, it is rare to find illiterate women so close (and seemingly making a major determining impact) on the lives of two of the most literate men of the nineteenth century. Drawing on Marx and Engels’ sprawling correspondence, as well as contemporary censuses, this paper seeks to uncover how much we can ever truly know about these two women? How much of a role did they actually play in Engels’ political and literary work? And how much have their real lives been covered up with a Marxist romanticizing of two proletarian, illiterate factory workers?
The Burns family appeared to have lived in the Deansgate area of Manchester from the 1820s. The only direct documentary evidence relating to the parentage of the Burns sisters is contained in Lydia’s marriage certificate of 1878 which names her father as Michael Burns, dyer. This is probably the Michael Burns, dyer, listed in the Manchester Directory of 1829 at 32 Cotton Street and in the 1832 Directory at 76 Henry Street, Ancoats. Burns was born in Ireland around 1790 and married Mary Conroy in Manchester in 1821; they had four children, of whom only two (Mary and Lizzie) survived into adulthood. The family lived at various addresses in Deansgate and Mary Conroy died sometime after 1827. Michael remarried, to Mary Tuomey, in 1835 and they had three children, of whom only one, Thomas, survived to adulthood. By 1853, Michael and Mary were living in the Workhouse for Sick and Infirm Poor in New Bridge Street, where Michael died in 1858, then buried at St. Patrick’s Roman Catholic Church in Miles Plattting. As of the 1861 Census, Mary was still at the Workhouse.
It is clear that Mary and Lizzie were no longer with the new family at the time of the 1841 Census. It is possible that the girls also abandoned factory work and wretched living conditions in the hovels of the Deansgate area and became domestic servants in the homes of more affluent families. According to the 1841 Census Returns, a Mary Burn, aged twenty, was employed as a female servant in the Deansgate house of George Chadfield, a master painter; and an Elizabeth Burns, aged fifteen, was acting as domestic servant to a family named Fothergill in Faulkner Street, near Piccadilly. ‘This is not in itself conclusive evidence but if these are the Burns sisters, then the experience they gained in service would have equipped them for their positions in later years as keepers of the Engels’ household.’ It is interesting to think that imagining the Burns sister as factory workers can be incorporated into Marxist narratives, but that they were potentially servants (a form of labour about which Marx and Engels had little to say) has been ignored.
Roy Whitfield states that Mary Burns and Engels met shortly after his first arrival in Manchester in 1842 and that she helped him with the investigations of housing and factory conditions in the city that eventually became Conditions of the Working Class in England. There is little direct evidence of this and none of Engels’ correspondence from 1842-44 has survived. The Ermen & Engels mill was in Deansgate, though, so their meeting there is definitely plausible. And they may have attended meetings together at the Hall of Science in Manchester, founded by Robert Owens.  Yvonne Kapp says that Engels met Mary Burns, ‘a mill-hand then aged 19’, in Eccles in 1842. In 1898, Eleanor Marx, who knew her personally, described her to Karl Kautsky: as a ‘Manchester (Irish) factory girl quite uneducated though she could read and write a little.’ Likewise, Edmund Wilson’s description in his 1941 work To the Finland Station, ring psychologically true, even if some of it remains unsubstantiated:
“He [Engels] was having a love affair with an Irish girl named Mary Burns who worked in the factory of Ermen & Engels and had been promoted to run a new machine called a “self-actor.” She seems to have been a woman of some independence of character, as she is said to have refused his offer to relieve her of the necessity of working. She had, however, allowed him to set up her and her sister in a little house in the suburb of Salford, where the coal-barges and chimneys of Manchester gave way to the woods and the fields. Mary Burns was a fierce Irish patriot and she fed Engels’ revolutionary enthusiasm at the same time that she served him as guide to the infernal abysses of the city.”
Moreover, it is worth considering what Burns would have thought of Engels’ first book. At one point in Conditions of the Working Class, he baldly declaimed that ‘In the throstle room at the cotton mill at Manchester in which I was employed, I do not remember to have seen one single tall, well-built girl; they were all short, dumpy and badly-formed, decidedly ugly in the whole development of the figure.’ Likewise, the book employs a number of regular anti-Irish tropes about the unhygienic, drunken, lazy, racially inferior Irish, which presumably would not have appealed to Mary Burns.
All of this is imaginatively explored in Frank McGuinness’ 1989 play Mary and Lizzie, which reconstructs both women. At the end of the play, “Lizzie” accurately forecasts that ‘you will be remembered, because you loved the earth… I will be remembered by a line in your life. Frederick Engels lived with two Irish women, Mary and Lizzie Burns. Little does that tell. Little do they know.’ Nonetheless, “Lizzie” does also recount her and her sister’s important role in Engels’ life and career: ‘Years ago in this country they say two women met a man and they went walking through Manchester. The women gave the man safe passage through the dangerous poor.. .They showed him the poor and they showed him their father and they showed their race and themselves to him’. In another scene, “Jenny von Westphalen”, Marx’s wife, questions the Burns sisters’ sexual propriety before reading some of the more overtly anti-Irish passages from Condition of the Working Class to the sisters; ‘Shall I tell you what he’s said… He’s named your race… Do you think he loves you?’
While we have no direct evidence as to how Mary Burns and Friedrich Engels met, they certainly were in a relationship by 1845, when they traveled together to Brussels. And in a letter from April of 1846 to his fellow communist, Emil Blank, Engels referred to her euphemistically as ‘my wife’. They were never formally married. A letter from January 1848 seems to be the first recorded example of Engels mentioning her to Marx, though the context makes it clear that Marx knows of her already (the specific context is an accusation from Sibylle Hess, wife of the communist and proto-Zionist Moses Hess, that Engels had sexually assaulted her). And certainly Marx knew of Burns as early as March 1846.
Freddie and Mary
By May 1854 Engels and Mary Burns were living together. This apparently caused some scandals with unnamed ‘Philistines’ in Manchester, about whom he complained to Marx and as a result of whom he took on additional lodgings. But this appears to have been for show and Engels continued to live with Burns. In an article for the Manchester Guardian on 10 October 1934, Moses Baritz, ‘a well-known figure in political and musical circle in Manchester of that period’, established a number of definite addresses at which Engels lived during his time in Manchester: 70 Great Ducie Street, Strangeways, 6 Thorncliffe Grove, Oxford Road (where Mary Burns) and 252 Hyde Road, Gorton, where both Mary and Lizzie Burns lived also and where Mary Burns died in January 1863. The houses he did rent were often in newly built areas of Manchester, where there was less of a sense of community thus less chance of his relationship with Mary Burns being discovered. When Marx died, Engels purged their collected correspondence of a large amount of letters that mentioned him (Engels). Their surviving letters from 1853 to ’63, now contain 403 letters from Marx but only 185 from Engels, suggesting that Engels destroyed over 200 of the letters he had written to Marx. ‘It seems clear that Engels’ purpose was to remove all references to his personal life with Mary Burns and to the methods he had employed to try to disguise his dual existence during those years.’
In 1856, Engels visited Ireland with Mary Burns, taking a circular route: Dublin to Galway, south to Kerry and looping back up to Dublin. Engels also made use of Mary as a supposedly safe recipient for his mail; already in 1851 he was encouraging Marx to place any politically incriminating letters ‘under seal with Mary’, in case of his house being searched by the authorities. Marx ended a letter of May 1862 by giving his greetings to ‘Mrs Bortman and sister’, a reference to the fact that Engels was renting accommodation on Hyde Road in Manchester under the assumed name of Frederick Boardman, with Mary Burns as Mary Boardman and presumably Lizzie Burns also taking an assumed name. An economic downturn caused by the US Civil War had forced Engels to economise his living expenses and ‘I’m living with Mary nearly all the time now so as to spend as little money as possible’. ‘Mary Boardman’ and her sister ‘Elizabeth Byrne’ are listed in 1861 census for 7 Rial Street; these are probably the Burns sisters. Engels was listed in the same census as living a half mile away at 6 Thorncliffe Grove. Mary Burns died in 1863, apparently from a long-term health issue. She remains a cipher; there are no known images of her and we do not even know where she was buried.
One Calamity is a Distraction from the Other
The death of Mary Burns was almost the occasion for a split in Engels’ longstanding collaboration with Marx. Writing to the “Moor” on 7 January 1863, Engels informed him that
“Mary is dead. Last night she went to bed early and, when Lizzy wanted to go to bed shortly before midnight, she found she had already died. Quite suddenly. Heart failure or an apoplectic stroke. I wasn’t told till this morning; on Monday evening she was still quite well. I simply can’t convey what I feel. The poor girl loved me with all her heart.”
Engels was presumably maintaining a separate residence at this time. Marx’s response was, to say the least, less than sympathetic. The news of Burns’ death ‘surprised no less than it dismayed me’ and Marx proceeded to compare Burns’ death and Engels’ grief to his own financial woes: ‘The devil alone knows why nothing but ill-luck should dog everyone in our circle just now.’ Marx went on to detail his bills with the butcher and baker and with his children’s schools. ‘It is dreadfully selfish of me to tell you about these horreurs at this time. But it’s a homeopathic remedy. One calamity is a distraction from the other.’ The obvious inference was that Marx was seeking cash from his patron. In a clipped letter five days later (an unusual pause in their otherwise almost daily correspondence), Engels bristled at the ‘frosty view’ that Marx had taken. Even ‘philistine acquaintances’ had shown better sympathies than his old friend. He bluntly suggested Marx take out a loan to cover his bills.  Marx may have been reflecting the frostiness of his wife, Jenny Marx, who once referred to Mary Burns as ‘Lady Macbeth’ and clearly saw in her an unwelcome addition to their lives. On 24 January, after a yawning eleven-day gap in their correspondence, Marx wrote a long letter to apologise for his ‘heartlessness’, though most of the letter was still taken up with his own financial problems and a plan to declare himself insolvent. He now claimed that the death of Mary Burns had affected him ‘as if my nearest and dearest had died.’ Two days later, Engels wrote to thank him for his ‘candid’ apology.
You yourself have now realized what sort of impression your last letter but one had made on me. One can’t live with a woman for years on end without being fearfully affected by her death. I felt as though with her, I was burying the last vestige of my youth. When your letter arrived she had not yet been buried. That letter, I tell you, obsessed me for a whole week; I couldn’t get it out of my head. NEVER MIND. Your last letter made up for it and I’m glad that, in losing Mary, I didn’t also lose my oldest and best friend.
The issue was put to bed, and importantly Engels included specific details as to how he would soon secure funds for Marx. Just over a year later, by April 1864, Marx was including his ‘Kindest regards’ to Lizzie Burns in his letters, suggesting that her relationship with Engels was now in place.
My Wife is a Revolutionary Irishwoman
Fig. 2: Sketch of Lizzie Burns by Engels, ca. 1869
We have far greater details about Lizzie, including, importantly, a photograph and a sketch by Engels (see Figure 2). Marx ended a letter of September 1864 with his ‘Regards to Madame Liz’ and also called her Engels’ ‘“Irish” lady-friend.’ suggesting more familiarity and even affection and playfulness. Perhaps he was keen to avoid a repeat of their almost-schism of January 1863. Conversely, would it be too much to interpret a veiled meaning in Marx’s closing message of a letter of August 1865: ‘Kindest regards to you from the whole family, and from me to Mrs Lizzy.’ Was it still clear that the Marx family, if not Marx himself, still looked askance at Engels’ Irish wives?
For almost the entirety of their relationships, Engels and Lizzie Burns were never formerly married though he did refer to her as wife, describing her to the socialist activist Ludwig Kugelmann as ‘my dear spouse’. Discussing her in 1870 with Natalie Liebknecht, wife of the SDP founder Wilhelm Liebknecht and mother of the Spartacist Karl Liebnecht, Engels said quite simply: ‘My wife is a revolutionary Irishwoman’. She does seem to have been an ardent nationalist, influencing Marx’s daughter Eleanor who briefly became known within their family as ‘the poor neglected nation’, such were her Fenian sympathies. Eleanor also signed letters to Burns with the sobriquet ‘Eleanor, F.S.’ (Fenian Sister). Lizzie knew various Irish songs from her youth, which she relearned after Jenny Marx, another of Marx’s daughters, gave her a copy of Thomas Moore’s Irish Melodies in August 1869. Engels, Lizzie and Eleanor Marx all visited Ireland together in September 1869, visiting Dublin, Wicklow, Cork, and Killarney. Engels described the trip as a success and sarcastically noted that Eleanor Marx and Lizzie Burns both ‘returned even hiberniores [more Irish] than when they departed.’ When various members of Marx and Engels’ circle published pro-Fenian articles, Lizzie was apparently ‘grateful’ and ‘absolutely enthusiastic’. There were ‘rejoicings’ in the Engels-Burns in December 1870 when convicted Fenians received amnesties.
That Marx encouraged Lizzie’s membership in the International Working Men’s Association obviously points to where her political sympathies lay. Conversely, certain hints of condescension towards her can be heard in Engels and Marx’s letters; Engels made fun of her pronouncing of Henri Rochefort, a French left-wing journalist as ‘Rushforth’ and disdainfully called her friend, Mrs Chorlton, ‘the fatty’. When the French communard Eugène Dupont arrived in Manchester in July 1870, Marx sought to have Lizzie hired as his maid, perhaps telegraphing how Marx continued to view Lizzie Burns, both in terms of her gender and her social background. Engels’ response was that ‘a reliable housemaid is damned difficult to drum up in a hurry’ but ‘Lizzie cannot leave the house because of her knee which, as a result of her unrest and impatience, is not getting better as quickly as it should.’
In November 1868, Lizzie Burns used a trip to friends in Lincolnshire as a political-anthropological fact-finding mission, reporting back to Engels about the gang system used by ‘patriarchal’ farm labourers there. She travelled widely with Engels, visiting Hamburg, Schleswig and Copenhagan in the summer of 1867, but apparently suffering terribly from seasickness. This seasickness may also have been something more serious, By November 1868, Engels was writing to Marx about her health, which would soon become a regular theme. Initially he described this as ‘congestions to the head’, but early the following year he was more specific: ‘Lizzie gets violent gastric catarrh, which I treated for a long while, and scarcely is this over, and she gets, as the result of an injury to her toe, an inflammation of the lymph ducts in her foot and leg, which could have become very unpleasant, but is now nearly over’. She recovered in late January 1860 but by March she was bedridden again with what Engels variously described as ‘bronchitis’, ‘a bad cold’, ‘pleurisy’, ‘exudation on the right lung’ and ‘catarrh in the lungs’. She was slowly recovering and ‘on a strengthening diet.’
In 1870, Engels and Burns left Manchester for London; the immediate reason was the ending of Engels’ much hated tenure at his family’s factory. Some tensions, due to unnamed causes, between Burns and her family also played a role: ‘My move to London late in summer has now been decided. Lizzie has told me that she would like to leave Manchester, the sooner the better; she has had some rows with relations, and she is fed up with the whole business here.’ It is quite plausible that her unmarried cohabitation with a German communist had irked her family. On their arrival in London they resided at 122 Regent’s Park – then, as now, an up-market locale – and Engels continued his practice of using Burns as a safe recipient for his politically sensitive correspondence. ‘If you write to Miss Burns you need neither an inside envelope, nor to make any mention of my name whatever. I open everything myself.’ He continued to refer to as his wife and in a letter of 1872 he even began to call her ‘Mrs Engels’
The move to London may have helped her health in the short-term, but by March 1877 her health declined, necessitating recuperative trips to Brighton. A trip to Ramsgate in July 1877 failed to have the desired positive effect; her appetite remained weak. Engels was ‘beginning to get seriously alarmed.’ She had a ‘serious crisis’ in her health on 22 July after which she slowly recovered. Her lingering health problems prevented Engels from completing a French translation of the Communist Manifesto. On 12 September 1878, at 1.30am, she ‘died peacefully after a long illness.’ She and Engels had been legally wed the previous evening; they were married according to the rites of the Church of England by Rev. W.B. Galloway of St. Mark’s Church, close to their home at 122 Regent’s Park Road. Burns was buried in St. Mary’s Cemetery, a Catholic graveyard, in Kensal Green in London. Her grave (see Figure 3) was marked with a Celtic cross and the epitaph:
“In memory of
wife of Frederick Engels
born August 6th 1827 died September 12th 1878
The gravestone as it currently exists is in shabby condition but appears to have had its engraving recently retouched.
Fig. 3: The Grave of Lizzie Burns, [Photo courtesy of Joe Dwyer / @JoeEDwyer]
After Lizzie’s death, Engels continued to have contact with her niece, Mary Ellen Burns (1860-1928), generally referred to, for unclear reasons, as “Pumps”. Pumps was the daughter of the Burns sisters’ half-brother, Thomas, who owned a fish shop in Manchester. Engels’ support seems to have been as much out of duty as affection, though prior to Lizzie Burns’ death Engels did refer to her in terms that suggested he had informally adopted her. There are references in Marx’s letters from 1881 and ’82 that speak to his irritability around Pumps. She flirted with various visitors to the Engels house, leading one émigré socialist, Leo Hartmann, to ask Engels’ permission to marry her in June 1881, not realising that her flirtations with him had apparently been intended to make another visitor, Karl Kautsky, jealous. By 1882 she had married a hapless accountant, Percy Rosher, becoming Mary Ellen Rosher and giving birth to a baby named Lilian. Marx would later tell his daughter, Laura Lafargue, that he found the baby to have a livelier intellect than the mother. Their second surviving child, Charles, was born at the start of 1885 and baptized in the Church of England. Engels regularly gave subventions to Percy Rosher’s luckless business adventures and bequeathed the couple the handsome sum of £2300 in his will. With the death of Engels in 1895 and thus perhaps their financial lifeline gone also, they sailed from Liverpool to Boston, via Queenstown (Cobh) in May 1898, settling in Norfolk, Massachesetts. Pumps died there in 1928.
Why Does This Matter?
The Burns sisters can clearly be placed in broader histories of the Irish Diaspora, where women often gained newfound freedoms denied them “at home” whilst continuing to face regular gendered stereotypes as Irish women. Clearly both Mary and Lizzie were freethinking and willing to forge their own lifestyles, ones that certainly did not align with standard mid-Victorian Irish or British codes of social propriety. What we know of both sisters’ politics is also telling; in Engels or Marx’s letters they are always assumed to be Fenian sympathisers, yet these descriptions seem to lack content or three dimensions: “Fenian” was perhaps an identity placed upon them, rather than a positive descriptor of complicated viewpoints. We can assume that both sisters were communists, or at the very least that they were comfortable enough with communism to have long-term relationships with an committed foreign-born communist. And yet there is the tantalizing piece of evidence of Lizzie Burns’ marriage and burial; certain “traditional” social niceties and norms clearly mattered to her. She clearly preferred to die a wife than a “woman living in sin”. And an Irish-inflected Catholicism remained of a piece with all that. Both sisters’ lives illustrate all the contradictions and complexities that existed just below the surface of the simple label of “Irish” in the nineteenth century.
 Georg Weerth, a friend of Engels, wrote a poem called Mary which references Tipperary (‘I should like the clover of Tipperary/To grow over and choke the rose of England’), which is perhaps the source of the idea that she was from Tipperary. Roy Whitfield. Frederick Engels in Manchester: The Search for a Shadow (Salford: Working Class Movement Library, 1988), 21
 The Young Karl Marx, Raoul Peck, dir. (2017)
 E.P. Thompson. The Making of the English Working Class (New York: Vintage, 1966), 12
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 69
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 69-70
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 22
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 3, 17
 Mick Jenkins. Frederick Engels in Manchester (Manchester: Lancashire & Cheshire Communist Party, 1951), 10, 17
 Yvonne Kapp. Eleanor Marx, Vol. 1: Family Life (1855-1883) (New York: International Publishers, 1972), 109.
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 19
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 19
 Aidan Beatty, ‘Marx and Engels, Ireland, and the Racial History of Capitalism’. Journal of Modern History, Vol. 91 (2019), 817-818
 Frank McGuinness. Plays Two (London: Faber & Faber, 2002) 53, 64, 74
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 23-24
 Letter 17, Letter from Engels to Emil Blank, 3 April 1846, MECW 38
 Letter 52, Letter from Engels to Marx, 14 January 1848, MECW 38
 Letter 3 [Appendix], Letter from Jenny Marx to Karl Marx, 24 March 1846, MECW 38.
 Letter 222, Engels to Marx, 1 May 1854, MECW 39
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 6
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 33, 35-36
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 7
 Beatty, ‘Marx and Engels’ (2019), 815-816
 Letter 182, Marx to Engels, 16 June 1851, MECW 38
 Letter 216, Letter from Marx to Engels, 27 May 1862, MECW 41
 Letter 202, Letter from Engels to Marx, 28 February 1862, MECW 41
 Whitfield, ‘Frederick Engels in Manchester’ (1988), 35
 Letter 266, Engels to Marx, 7 January 1863, MECW 41
 Letter 267, Marx to Engels, 8 January 1863, MECW 41
 Letter 268, Engels to Marx, 13 January 1863, MECW 41
 Letter 3 [Appendix], Letter from Jenny Marx to Karl Marx, 24 March 1846, MECW 38
 Letter 269, Marx to Engels, 24 January 1863, MECW 41
 Letter 270, Engels to Marx, 26 January 1863, MECW 41
 Letter 310, Marx to Engels, 19 April 1864, MECW 41. A letter from later that year ends with ‘Regards to Madame Liz’, suggesting even more familiarity and playfulness; Letter 339, Marx to Engels, 7 September 1864, MECW 41
 Letter 339, Marx to Engels, 7 September 1864, MECW 41; Letter 129, Marx to Engels, 13 February 1866, MECW 42
 Letter 92, Marx to Engels, 5 August 1865, MECW 42
 Letter 50, Engels to Ludwig Kugelmann, 31 July 1868, MECW 43
 Letter 56, Engels to Natalie Liebknecht, 19 December 1870, MECW 44
 Letter 51, Marx to Engels, 4 August 1868 and Letter 132, Marx to Engels, 14 December 1868, , MECW 43
 Kapp, ‘Eleanor Marx’,1(1972), 89
 Letter 239, Engels to Jenny Marx (daughter), 8 August 1869, MECW 43
 Letter 250, Engels to Marx, 27 September 1869, MECW 43
 Letter 302, Engels to Marx, 13 March 1870 and Letter 327, Engels to Marx, 1 May 1870, MECW 43
 Letter 56, Engels to Natalie Liebknecht, 19 December 1870, MECW 44
 Letter 53, Marx to Engels, 25 January 1865, MECW 42
 Letter 287, Engels to Marx, 11 February 1870, MECW 43
 Letter 98, Engels to Marx, 28 October 1868, MECW 43
 Letter 342, Marx to Engels, 5 July 1870, MECW 43
 Letter 343, Engels to Marx, 6 July 1870, MECW 43
 Letter 107, Engels to Marx, 10 November 1868, MECW 43
 Letter 230, Engels to Marx, 26 June 1867 & Letter 237, Engels to Marx, 11 August 1867, MECW 42
 Letter 143, Engels to Marx, 19 January 1869, MECW 43
 Letter 145, Engels to Marx, 25 January 1869, Letter 170, Engels to Marx, 15 March 1869, Letter 171, Engels to Marx, 18 March 1869, and Letter 173, Engels to Marx, 21 March 1869, MECW 43
 Letter 176, Engels to Marx, 2 April 1869, MECW 43
 Letter 294, Engels to Marx, 22 February 1870, MECW 43
 Letter 109, Engels to Carlo Carieor, 28 July 1871, MECW 44
 Letter 186, Engels to Theodor Cuno, 24 January 1872, MECW 44
 Letter 259, Engels to Hermann Jung, 1 October 1872, MECW 44
 Letter 145, Engels to Friedrich Lessner, 4 March 1877, Letter 147, Engels to Marx, 6 March 1877, Letter 172, Engels to Wilhelm Liebknecht, 2 July 1877, MECW 45
 Letter 173, Engels to Marx, 15 July 1877, Letter 175, Engels to Marx, 19 July 1877, MECW 45
 Letter 177, Engels to Marx, 24 July 1877, MECW 45
 Letter 198, Marx to Friedrich Adolph Sorge, 19 October 1877, MECW 45
 Letter 227, Engels to Rudolf Engels, 12 September 1878, MECW 45
 Kapp, ‘Eleanor Marx’ 1 (1972), 191
 Kapp, ‘Eleanor Marx’ 1 (1972), 186
 In a November 1875 letter to his brother Rudolf, Engels refers to Lizzie as ‘my wife’ and Mary Ellen as ‘our little one’ Letter 69, Engels to Rudolf Engels, 9 November 1875, MECW 45. The following year he called her ‘our Pumps’; Letter 78, Engels to Philipp Pauli, 25 April 1876, MECW 45
 Letter 59, Marx to Jenny Longuet [Jenny Marx], 6 June 1881, MECW 46
 Letter 128, Marx to Engels, 4 April 1882, MECW 46
 Letter 188, Marx to Laura Lafargue [Laura Marx], 9 October 1882, MECW 46
 London Metropolitan Archives, Board of Guardian Records, 1834-1906, Church of England Parish Registers, 1754-1906, P81/MRY/003
 Letter 195, Engels to Laura Lafargue, 28 July 1894; Letter 242, Engels to Ludwig Schorlemmer, 3 January 1895; Will and Codicil of Frederick Engels, 29 July 1893; Engels’ Letter to the Executors of his Will, 14 November 1894, MECW 50
 National Archives, Washington, D.C.; Series Title: Passenger Lists of Vessels Arriving at Boston, Massachusetts, 1891-1943; NAI Number: 4319742; Record Group Title: Records of the Immigration and Naturalization Service, 1787-2004; Her obituary is listed in the Boston Globe, 12 October 1928