| Engels to Laura Lafargue. 2 January |
| Engels to August Bebel. 5 January |
| Engels to Ludwig Kugelmann. 10 January |
| Engels to Conrad Schmidt. 11 January |
| Engels to Friedrich Adolph Sorge. 12 January |
| Engels to Florence Kelley-Wischnewetsky. 12 January |
| Engels to Paul Lafargue. 14 January |
| Engels to Karl Kautsky. 18 January |
| Engels to Karl Kautsky. 28 January |
| Engels to Hermann Schluter. 31 January |
| Engels to Laura Lafargue. 4 February |
| Engels to Karl Kautsky. 7 February |
| Engels to Laura Lafargue. 11 February |
| Engels to John Lincoln Mahon. 14 February |
| Engels to Karl Kautsky. 20 February |
| Engels to John Lincoln Mahon. 21 February |
| Engels to Friedrich Adolph Sorge. 23 February |
| Engels to Paul Lafargue. 12 March |
| Engels to Conrad Schmidt. 12 March |
| Engels to Paul Lafargue. 21 March |
| Engels to Paul Lafargue. 23 March |
| Engels to Paul Lafargue. 25 March |
| Engels to Paul Lafargue. 27 March |
| Engels to Paul Lafargue. 1 April |
| Engels to Wilhelm Liebknecht. 4 April |
| Engels to Wilhelm Liebknecht. 5 April |
| Engels to Paul Lafargue. 10 April |
| Engels to Wilhelm Liebknecht. 17 April |
| Engels to Karl Kautsky. 20 April |
| Engels to Paul Lafargue. 30 April |
| Engels to Paul Lafargue. 1 May |
| Engels to Paul Lafargue. 1 May |
| Engels to Paul Lafargue. 2 May |
| Engels to Laura Lafargue. 7 May |
| Engels to Friedrich Adolph Sorge. 11 May |
| Engels to Paul Lafargue. 11 May |
| Engels to Eleanor Marx-Aveling. 13 May |
| Engels to Laura Lafargue. 14 May |
| Engels to Paul Lafargue. 16 May |
| Engels to Paul Lafargue. 17 May |
| Engels to Karl Kautsky. 21 May |
| Engels to A F Robinson. 21 May |
| Engels to Paul Lafargue. 24 May |
| Engels to Paul Lafargue. 25 May |
| Engels to Paul Lafargue. 27 May |
| Engels to Friedrich Adolph Sorge. 8 June |
| Engels to Laura Lafargue. 11 June |
| Engels to Conrad Schmidt. 12 June |
| Engels to Paul Lafargue. 15 June |
| Engels to Laura Lafargue. 28 June |
| Engels to Nikolal Danielson. 4 July |
| Engels to Paul Lafargue. 5 July |
| Engels to Pasquale Martignetti. 9 July |
| Engels to Nikolal Danielson. 15 July |
| Engels to Friedrich Adolph Sorge. 17 July |
| Engels to Friedrich Adolph Sorge. 20 July |
| Engels to Pasquale Martignetti. 20 July |
| Engels to Valerian Smirnov. 25 July |
| Engels to Friedrich Adolph Sorge. 17 August |
| Engels to Wilhelm Liebknecht. 17 August |
| Engels to Eduard Bernstein. 22 August |
| Engels to Hermann Engels. 22 August |
| Engels to Laura Lafargue. 27 August |
| Engels to Laura Lafargue. 1 September |
| Engels to Laura Lafargue. 9 September |
| Engels to Karl Kautsky. 15 September |
| Engels to Friedrich Adolph Sorge. 26 September |
| Engels to Paul Lafargue. 3 October |
| Engels to Wilhelm Liebknecht. 3 October |
| Engels to Laura Lafargue. 8 October |
| Engels to Friedrich Adolph Sorge. 12 October |
| Engels to Laura Lafargue. 17 October |
| Engels to Conrad Schmidt. 17 October |
| Engels to Max Hildebrand. 22 October |
| Engels to 0 A Ellissen. 22 October |
| Engels to Laura Lafargue. 29 October |
| Engels to Wilhelm Liebknecht. 29 October |
| Engels to Pasquale Martignetti. 9 November |
| Engels to August Bebel. 15 November |
| Engels to J H Johnson, J Johnson and G B Ellis. 15 November |
| Engels to Paul Lafargue. 16 November |
| Engels to Laura Lafargue. 16 November |
| Engels to Paul Lafargue. 18 November |
| Engels to Jules Guesde. 20 November |
| Engels to Pasquale Martignetti. 30 November |
| Engels to Victor Adler. 4 December |
| Engels to Nikolai Danielson. 5 December |
| Engels to Friedrich Adolph Sorge. 7 December |
| Engels to Conrad Schmidt. 9 December |
| Engels to Gerson Trier. 18 December |
| Engels to Natalie Liebknecht. 24 December |
| Engels to Ludwig Kugelmann. 30 December |