| Engels to Laura Lafargue. 1 January |
| Engels to Hermann Schluter. 1 January |
| Engels to Karl Kautsky. 13 January |
| Engels to Hermann Schluter. 13 January |
| Engels to Hermann Schluter. 17 January |
| Engels to August Bebel. 19 January |
| Engels to Paul Lafargue. c. 25 January |
| Engels to Florence Kelley-Wischnewetzky. 4 February |
| Engels to Wilhelm Liebknecht. 4 February |
| Engels to Florence Kelley-Wischnewetzky. 10 February |
| Engels to Nikolai Danielson. 11 February |
| Engels to Pyotr Lavrov. 12 February |
| Engels to Karl Kautsky. 14 February |
| Engels to Hermann Schluter. 22 February |
| Engels to Laura Lafargue. 8 March |
| Engels to Richard Stegemann. 26 March |
| Engels to Johann Philipp Becker. 2 April |
| Engels to August Bebel. 4 April |
| Engels to Pasquale Martignetti. 11 April |
| Engels to Karl Kautsky. 16 April |
| 162 Engels to Laura Lafargue. 16-17 April |
| Engels to Eduard Bernstein. After 16 April |
| Engels to Nikolai Danielson. 23 April |
| Engels to Vera Zasulich. 23 April |
| Engels to Richard Stegemann. 5 May |
| Engels to Eduard Bernstein. 15 May |
| Engels to Hermann Schluter. 15 May |
| Engels to Paul Lafargue. 19 May |
| Engels to Pasquale Martignetti. 19 May |
| Engels to Laura Lafargue. 29 May |
| Engels to Nikolai Danielson. 3 June |
| Engels to Friedrich Adolph Sorge. 3 June |
| Engels to John Lincoln Mahon. 12 June |
| Engels to Pasquale Martignetti. 13 June |
| Engels to Johann Philipp Becker. 15 June |
| Engels to Eduard Bernstein. 16 June |
| Engels to Laura Lafargue. 16 June |
| Engels to Hermann Schluter. 16 June |
| Engels to August Bebel. 24 June |
| Engels to Hermann Schluter. 1 July |
| Engels to Laura Lafargue. 4 July |
| Engels to Gertrud Guillaume-Schack. c. 5 July |
| Engels to John Lincoln Mahon. c. 11 July |
| Engels to Laura Lafargue. 23 July. |
| Engels to August Bebel. 24 July |
| Engels to Eduard Bernstein. 24 July |
| Engels to Nikolai Danielson. 8 August |
| Engels to Laura Lafargue. 8 August |
| Engels to Karl Kautsky. 16 August |
| Engels to Nikolai Danielson. 25 August |
| Engels to Hermann Schluter. 26 August |
| Engels to Karl Kautsky. 6 September |
| Engels to Hermann Schluter. 9 September |
| Engels to Karl Kautsky. 10 September |
| Engels to Laura Lafargue. 22 September |
| Engels to Hermann Schluter. 23 September |
| Engels to Eduard Bernstein. 8 October |
| Engels to Hermann Schluter. 9 October |
| Engels to Laura Lafargue. 13 October |
| Engels to Karl Kautsky. 14 October |
| Engels to Pyotr Lavrov. 20 October |
| Engels to Salo Faerber. 22 October |
| Engels to August Bebel. 28 October |
| Engels to Laura Lafargue. 7 November |
| Engels to Hermann Schluter. 11 November |
| Engels to Nikolai Danielson. 13 November |
| Engels to Paul Lafargue. 14 November |
| Engels to August Bebel. November |
| Engels to Minna Kautsky. 26 November |
| Engels to Paul Lavigne. 1 December |
| Engels to Wilhelm Liebknecht. 1 December |
| Engels to Karl Kautsky. 2 December |
| Engels to Johann Philipp Becker. 5 December |
| Engels to Wilhelm Liebknecht. 5 December |
| Engels to Eduard Bernstein. 7 December |
| Engels to Paul Lafargue. 7 December |
| Engels to Hermann Schluter. 7 December |
| Engels to Ferdinand Domela Nieuwenhuis. 19 December |
| Engels to Pasquale Martignetti. 21 December |
| Engels to Hermann Schluter. 21 December |
| Engels to Laura Lafargue. 22 December |
| Engels to Wilhelm Liebknecht. 28 December |
| Engels to Johann Philipp Becker. 28 December |