| Engels to Ion Nadejde. 4 January |
| Engels to Nikolal Danielson. 5 January |
| Engels to Friedrich Adolph Sorge. 7 January |
| Engels to Wilhelm Liebknecht. 10 January |
| Engels to Hermann Schluter. 10 January |
| Engels to Pasquale Martignetti. 10 January |
| Engels to Hermann Schluter. 23 January |
| Engels to Paul Lafargue. 7 February |
| Engels to Hermann Schluter. 12 February |
| Engels to Hermann Schluter. 19 February, |
| Engels to Friedrich Adolph Sorge. 22 February |
| Engels to Florence Kelley-Wlschnewetsky. 22 February |
| Engels to Wilhelm Liebknecht. 23 February |
| Engels to Ferdinand Domela Nieuwenhuls. 23 February |
| Engels to Laura Lafargue. 25 February |
| Engels to Wilhelm Liebknecht. 29 February |
| Engels to Hermann Schluter. 17 March |
| Engels to Paul Lafargue. 19 March |
| Engels to Margaret Harkness. c. 1 April |
| Engels to Laura Lafargue. 10-11 April |
| Engels to Florence Kelley-Wischnewetsky. 11 April |
| Engels to August Bebel. 12 April |
| Engels to Wilhelm Liebknecht. 16 April |
| Engels to Pasquale Martignetti. 20 April |
| Engels to Gabriel Deville. 27 April |
| Engels to Wilhelm Liebknecht. 29 April |
| Engels to Florence Kelley-Wischnewetsky. 2 May |
| Engels to Laura Lafargue. 9 May |
| Engels to Eleanor Marx-Aveling. 10 May |
| Engels to Hermann Schluter. 10 May |
| Engels to Florence Kelley-Wischnewetsky. 16 May |
| Engels to Amand Goegg. 2 June |
| Engels to Laura Lafargue. 3 June |
| Engels to Hermann Schluter. 15 June |
| Engels to Paul Lafargue. 30 June |
| Engels to Karl Kautsky. before 6 July |
| Engels to Laura Lafargue. 6 July |
| Engels to Friedrich Adolph Sorge. 11 July |
| Engels to Laura Lafargue. 15 July |
| Engels to Laura Lafargue. 23 July |
| Engels to Hermann Schluter. 28 July |
| Engels to Laura Lafargue. 30 July |
| Engels to Friedrich Adolph Sorge. 4 August |
| Engels to Laura Lafargue. 6 August |
| Engels to Eduard Bernstein. 9 August |
| Engels to Hermann Engels. 9 August |
| Engels to Friedrich Adolph Sorge. 28 August |
| Engels to Friedrich Adolph Sorge. 31 August |
| Engels to Wilhelm Liebknecht. 31 August |
| Engels to Friedrich Adolph Sorge. 4 September |
| Engels to Laura Lafargue. 5 September |
| Engels to Friedrich Adolph Sorge. 10 September |
| Engels to Friedrich Adolph Sorge. 11 September |
| Engels to Friedrich Adolph Sorge. 12 September |
| Engels to Florence Kelley-Wischnewetsky. 18 September |
| Engels to The Editor of The New Yorker Volkszeitung. 18 September |
| Engels to The Editor of The Chicagoer Arbeiter-Zeitung. 18 September |
| Engels to Hermann Engels. 28 September |
| Engels to Conrad Schmidt. 8 October |
| Engels to Friedrich Adolph Sorge. 10 October |
| Engels to Louise Kautsky. 11 October |
| Engels to Laura Lafargue. 13 October |
| Engels to Nikolal Danielson. 15 October |
| Engels to Karl Kautsky. 17 October |
| Engels to August Bebel. 25 October |
| Engels to Laura Lafargue. 24 November |
| Engels to Paul Lafargue. 4 December |
| Engels to Friedrich Adolph Sorge. 15 December |
| Engels to E Walter. 21 December |