| Engels to Paul Lafargue 3 January |
| Engels to Pyotr Lavrov 4 January |
| Engels to Giuseppe Canepa 9 January |
| Engels to Karl Kautsky 9 January |
| Engels to Pyotr Lavrov 10 January |
| Engels to George William Lamplugh 10 January |
| Engels to Henri Rave 10 January |
| Engels to Victor Adler 11 January |
| Engels to George William Lamplugh 12 January |
| Engels to Albert Delon 21 January |
| Engels to W Borgius 25 January [alt] |
| Engels to Filippo Turati 26 January |
| Engels to Richard Fischer 1 February |
| Engels to Karl Kautsky 13 February |
| Engels to Georg Von Gizycki 17 February |
| Engels to Eduard Bernstein 22 February |
| Engels to Friedrich Adolph Sorge 23 February |
| Engels to Adelheid Dworak and Julius Popp [Feb.] |
| Engels to Paul Lafargue 6 March |
| Engels to August Momberger 9 March |
| Engels to Victor Adler 20 March |
| Engels to Nikolai Danielson 20 March |
| Engels to Panait Musoiu 20 March |
| Engels to Friedrich Adolph Sorge 21 March |
| Engels to Victor Adler 22 March |
| Engels to Pablo Iglesias 26 March |
| Engels to Benno Karpeles 29 March |
| Engels to Hunter Watts 3 April |
| Engels to Laura Lafargue 11 April |
| Engels to Filippo Turati 12 April |
| Engels to Henry William Lee 16 April |
| Engels to Editorial Board of a French Socialist Newspaper 24 April |
| Engels to Carl Eberle 24 April |
| Engels to Laura Lafargue 11 May |
| Engels to Filippo Turati 11 May |
| Engels to Adolph Sorge 12 May |
| Engels to Boris Krichevsky 20 May |
| Engels to Georgi Plekhanov 21 May |
| Engels to Stanislav Mendelson 22 May |
| Engels to Georgi Plekhanov 22 May |
| Engels to Boris Krichevsky 31 May |
| Engels to Nikolai Danielson 1 June |
| Engels to Paul Lafargue 2 June |
| Engels to Witold Jodko-Narkevich 5 June |
| Engels to Stanislaw Zablocki 7 June |
| Engels to Karl Kautsky 19 June |
| Engels to Karl Kautsky 26 June |
| Engels to Otto Wachs end June-early July |
| Engels to Boris Krichevsky July |
| Engels to Laura Lafargue 4 July |
| Engels to Ludwig Schorlemmer 5 July |
| Engels to Editor of the Neue Zeit 9 July |
| Engels to Karl Kautsky 16 July |
| Engels to Victor Adler 17 July |
| Engels to Julius Motteler 21 July |
| Engels to Karl Kautsky 28 July |
| Engels to Laura Lafargue 28 July |
| Engels to Filippo Turati 31 July |
| Engels to Victor Adler 4 August |
| Engels to Pablo Iglesias 9-14 August |
| Engels to Eduard Bernstein 14 August |
| Engels to Thomas Clarke 15 August |
| Engels to Filippo Turati 16 August |
| Engels to Paul Lafargue 22 August |
| Engels to Eduard Bernstein 6 September |
| Engels to Eduard Bernstein 18 September |
| Engels to Laura Lafargue 2nd half Sept. |
| Engels to Karl Kautsky 23 September |
| Engels to Emile Vandervelde 21 October |
| Engels to Maria Mendelson 26 October |
| Engels to Georgi Plekhanov 1 November |
| Engels to Carl Hirsch 8 November |
| Engels to Eleanor Marx-Aveling 10 November |
| Engels to Friedrich Adolph Sorge 10 November |
| Engels to Laura Lafargue 12 November |
| Engels to August Bebel and Paul Singer 14 November |
| Engels to Eduard Bernstein 14 November |
| Engels to Laura Lafargue and Eleanor Marx-Aveling 14 November |
| Engels to Karl Kautsky 15 November |
| Engels to Eduard Bernstein 20 November |
| Engels to Karl Kautsky 22 November |
| Engels to Paul Lafargue 22 November |
| Engels to Jossif Atabekjanz 23 November |
| Engels to Nikolai Danielson 24 November |
| Engels to Wilhelm Liebknecht 24 November |
| Engels to Mrs Karpeles 30 November |
| Engels to Friedrich Adolph Sorge 4 December |
| Engels to Filippo Turati 4 December |
| Engels to Friedrich Adolph Sorge 12 December |
| Engels to Victor Adler 14 December |
| Engels to Witold Jodko-Narkiewicz 14 December |
| Engels to Laura Lafargue 17 December |
| Engels to Pyotr Lavrov 18 December |
| Engels to Paul Lafargue 18 December |
| Engels to George William Lamplugh 21 December |
| Engels to Victor Adler 22 December |
| Engels to Paul Singer 26 to 29 December |
| Engels to Victor Adler 27 December |
| Engels to Laura Lafargue 29 December |