| Engels to Wilhelm Liebknecht. 2 January |
| Engels to Florence Kelley-Wischnewetzky. 7 January |
| Engels to Wilhelm Liebknecht. 7 January |
| Engels to Laura Lafargue. 17 January |
| Engels to August Bebel. 20-23 January |
| Engels to Edward Pease. 27 January |
| Engels to Friedrich Adolph Sorge. 29 January |
| Engels to Florence Kelley-Wischnewetzky. 3 February |
| Engels to Ferdinand Domela Nieuwenhuis. 4 February |
| Engels to Pyotr Lavrov. 7 February |
| Engels to Nikolai Danielson. 3 February |
| Engels to Friedrich Adolph Sorge. 9 February |
| Engels to Laura Lafargue. 9 February |
| Engels to August Bebel. 15 February |
| Engels to Paul Lafargue. 16 February |
| Engels to Eduard Bernstein. 24 February |
| Engels to Florence Kelley-Wischnewetzky. 25 February |
| Engels to Wilhelm Liebknecht. 25 February |
| Engels to Hermann Schluter. 3 March |
| Engels to Florence Kelley-Wischnewetzky. 12 March |
| Engels to Pasquale Martignetti. 12 March |
| Engels to Hermann Schluter. 12 March |
| Engels to Laura Lafargue. 15-16 March |
| Engels to August Bebel. 18 March |
| Engels to Paul Lafargue. 20 March |
| Engels to Eleanor Marx-Aveling. 25 March |
| Engels to Vera Zasulich. 31 March |
| Engels to August Bebel. 12 April |
| Engels to Philipp Victor Pauli. 12 April |
| Engels to Laura Lafargue. 26 April |
| Engels to Friedrich Adolph Sorge. 29 April |
| Engels to Paul Lafargue. 7 May |
| Engels to Wilhelm Liebknecht. 12 May |
| Engels to F H Nestler & Melle's Verlag. 13 May |
| Engels to Eduard Bernstein. 22 May |
| Engels to Laura Lafargue. 23 May |
| Engels to Florence Kelley-Wischnewetzky. 3 June |
| Engels to Hermann Schluter. 3 June |
| Engels to Karl Kautsky. 2 July |
| Engels to Karl Kautsky. 4 July |
| Engels to Karl Kautsky. 8 July |
| Engels to Johann Philipp Becker. 9 July |
| Engels to Karl Kautsky. 26 July |
| Engels to Karl Kautsky. 31 July |
| Engels to Friedrich Adolph Sorge. 3 August |
| Engels to Karl Kautsky. 6 August |
| Engels to Karl Kautsky. 11 August |
| Engels to Florence Kelley-Wischnewetzky. 13-14 August |
| Engels to Eduard Bernstein. 14 August |
| Engels to August Bebel. 18 August |
| Engels to Karl Kautsky. 20 August |
| Engels to Eduard Bernstein. 20 August |
| Engels to Hermann Schluter. 20 August |
| Engels to Karl Kautsky. 23 August |
| Engels to Karl Kautsky. 24 August |
| Engels to Laura Lafargue. 24 August |
| Engels to Karl Kautsky. 25 August |
| Engels to Karl Kautsky. 26 August |
| Engels to Friedrich Adolph Sorge. 6 September |
| Engels to F H Nestier & Melle's Verlag. 11 September |
| Engels to Laura Lafargue. 13 September |
| Engels to August Bebel. 14 September |
| Engels to Friedrich Adolph Sorge. 16 September |
| Engels to Pasquale Martignetti. 17 September |
| Engels to Laura Lafargue. 24 September |
| Engels to Natalie Liebknecht. 25 September |
| Engels to Laura Lafargue. 2 October |
| Engels to August Bebel. 8 October |
| Engels to Eduard Bernstein. 9 October |
| Engels to Eduard Bernstein. 22 October |
| Engels to Laura Lafargue. 23 October |
| Engels to August Bebel. 23 October |
| Engels to Paul Lafargue. 26 October |
| Engels to Laura Lafargue. 2 November |
| Engels to Nikolai Danielson. 9 November |
| Engels to E T. 13 November |
| Engels to Laura Lafargue. 23 November |
| Engels to Laura Lafargue. 24 November |
| Engels to Hermann Schluter. 26 November |
| Engels to Karl Kautsky. 29 November |
| Engels to Friedrich Adolph Sorge. 29 November |
| Engels to Hermann Schluter. 7 December |
| Engels to Halliday Sparling. 7 December |
| Engels to Laura Lafargue. 13 December |
| Engels to Emil Engels. 22 December |
| Engels to Florence Kelley-Wischnewetzky. 28 December |