Sources: TxAu3
- Samuel L. Clemens to James Redpath and George L. Fall, 11 October 1871 · Hartford, Conn · UCCL00659
- Samuel L. Clemens to James Redpath and George L. Fall per Telegraph Operator, 8 December 1871 · Buffalo, N.Y · UCCL00687
- Samuel L. Clemens to Ira F. Hart, per Olivia L. Clemens, 12 January 1873 · Hartford, Conn · UCCL00855
- Samuel L. Clemens to James Redpath, 1 February 1874 · Hartford, Conn · UCCL01043
- Samuel L. Clemens to Cashier, First National Bank of Hartford, 04 February 1876 · Hartford, Conn · UCCL12995
- SLC to Unidentified, 17 April 1876 · Hartford, Conn · UCCL13785
- SLC to the American Publishing Co. · 17 April 1877 · Hartford, Conn · UCCL09794
- Samuel L. Clemens to Matthew H. Bartlett, October 1877 · 2nd of 2 · Hartford, Conn · UCCL11172
- Samuel L. Clemens to Andrew Chatto, 21 January 1878 · Hartford, Conn · UCCL02324
- Samuel L. Clemens to Joseph Blackburn Jones, 30 October 1879 · Hartford, Conn · UCCL12006
- SLC to Robert Chaffee Morgan, 14-27 1881 · Hartford or Branford, Conn · UCCL13650
- SLC to Karl and Hattie J. Gerhardt, 26 June 1881 · Branford, Conn · UCCL01978
- SLC to Benjamin H. Ticknor, 15 August 1881 · Elmira, N.Y · UCCL02007
- SLC to Andrew Chatto, 1 March 1883 · Hartford, Conn · UCCL12923
- Samuel L. Clemens to Henry (Harry) M. Clarke, 119 July 1883 · 2nd of 2 · Elmira, N.Y · UCCL13226
- Samuel L. Clemens to Henry (Harry) M. Clarke, 1–19 July 1883 · 1st of 2 · Elmira, N.Y · UCCL13225
- SLC to Joseph B. Gilder, 16 May 1886 · Hartford, Conn · UCCL11414
- SLC to Walter Lee Brown, 14 June 1886 · Hartford, Conn · UCCL03409
- OLC to Edward K. Root, 10 January 1887 · Hartford, Conn · UCCL12547
- SLC to Editors of the Century Magazine, 14 August 1887 · Elmira, N.Y · UCCL12920
- SLC to Franklin G. Whitmore, 25 August 1888 · Elmira, N.Y · UCCL11428
- SLC to Charles Calvin Ziegler, 14 April 1893 · Chicago, Ill · UCCL12661
- SLC to Jean Clemens, 12 January 1894 · New York, N.Y · UCCL03993
- SLC to OLC, 26 and 28 August 1896 · Guildford, England · UCCL05100
- SLC to Chatto & Windus, 23 March 1897 · London, England · UCCL10866
- SLC to the American Publishing Company, 6 February 1898 · Vienna, Austria · UCCL13789
- SLC to Edmund W. Gosse, 6 July 1899 · London, England · UCCL05651
- SLC to Augustus T. Gurlitz, 5 January 1901 · New York, N.Y · UCCL12193
- SLC to Virginia F. Boyle, 6 January 1902 · Riverdale, N.Y · UCCL06221
- SLC to William D. Howells, 11 August 1902 · York Harbor, Me · UCCL12922
- SLC to Gertrude Swain, 16 October 1902 · Riverdale, N.Y · UCCL06464
- SLC per IVL to Emily S. Hutchings, 14 November 1902 · Riverdale, N.Y · UCCL06487
- SLC to Unidentified, 23 December 1902 · Riverdale, N.Y · UCCL13564
- SLC to Charles S. and Elisabeth N. Fairchild, 20 July 1904 · Lee, Mass · UCCL06891
- SLC to Elias Cornelius Benedict, 15 September 1904 · New York, N.Y · UCCL12919
- SLC to Unidentified, 6 December 1905 · New York, N.Y · UCCL13786
- SLC Paula Lorch, 29–31 December 1905 · New York, N.Y · UCCL07281
- SLC to The Printer’s Home, January 1906 · New York, N.Y · UCCL12408
- SLC to Georgya E. Holly, 2–4 January 1906, New York, N.Y · UCCL13986
- SLC to Clara L. Clemens, 12 March 1907 · New York, N.Y · UCCL07675
- SLC to Evelyn Gifford, 28 June 1907 · Oxford, England · UCCL11825
- SLC to Unidentified, April 1908, Unknown place · UCCL14036
- SLC to Oscar Garett Wall, 8 November 1909 · Redding, Conn · UCCL13619
- SLC to Albert Bigelow Paine, 5 February–7 February 1910 · Hamilton, Bermuda · UCCL08555
- SLC to Unidentified, Unknown date · Unknown place · UCCL12463
- SLC to Unidentified, Unknown date · Unknown place · UCCL12400
- SLC to Richard Watson Gilder, unknown date, unknown place · UCCL13788
- SLC to Katie Leary, Unknown date · Unknown place · UCCL13790
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