Sources: CCamarSJ
- Samuel L. Clemens to Emeline B. Beach, 5 December 1867 · Washington, D.C · UCCL00169 CCamarSJ
- Samuel L. Clemens to Emeline B. Beach, 8 January 1868 · Washington, D.C · UCCL00174 CCamarSJ
- SLC to OLC, 10–13 September 1869 · Unknown place · UCCL09405 CCamarSJ
- Samuel L. Clemens to Emeline B. Beach, 4 February 1874 · Hartford, Conn · UCCL01044 CCamarSJ, CBev6
- SLC to OLC, 25 August 1881 · Boston, Mass · UCCL02015 CCamarSJ
- SLC to Susy (Olivia Susan) Clemens, 25 May 1882 · Hartford, Conn · UCCL09121 CCamarSJ
- SLC to OLC, 25 December 1885 · Hartford, Conn · UCCL10650 CCamarSJ
- SLC to Ulysses S. Grant, Jr., 1885, Unknown place · UCCL13347 CCamarSJ
- SLC to Rollin M. Daggett, 21 October 1886 · Hartford, Conn · UCCL03473 CCamarSJ
- SLC to Hartford City Government, 14 October 1888 · Hartford, Conn · UCCL08825 CCamarSJ
- SLC to Frederick J. Hall, 11 November 1889 · Hartford, Connecticut · UCCL13055 CCamarSJ
- SLC to Frederick J. Hall, 14 November 1889 · Hartford, Connecticut · UCCL13054 CCamarSJ
- (C. L.) Webster & Co., Webster to SLC, 14 November 1889 [circa · UCLC50470 CCamarSJ
- SLC to Susan Corey, 25 December 1889 · Hartford, Conn · UCCL10640 CCamarSJ
- SLC to Daniel Frohman, 2 February 1890 · New York, N.Y · UCCL04010 CCamarSJ
- SLC to Unidentified, 27 November 1891 · Berlin, Germany · UCCL04257 CCamarSJ
- SLC to Mary Mapes Dodge, 31 October 1893 · New York, N.Y · UCCL04479 CCamarSJ
- SLC to James M. Tuohy, 2 November 1898 · Vienna, Austria · UCCL05458 CCamarSJ, CtWep1
- SLC to James M. Tuohy, 8 November 1898 · Vienna, Austria · UCCL05463 CCamarSJ
- SLC to James M. Tuohy, 10 November 1898 · Vienna, Austria · UCCL05465 CCamarSJ
- SLC to James M. Tuohy, 3 March 1899 · Vienna, Austria · UCCL05554 CCamarSJ
- SLC to James M. Tuohy, 22 March 1899 · Vienna, Austria · UCCL05567 CCamarSJ
- SLC to James M. Tuohy, 30 October 1899 · London, England · UCCL05697 CCamarSJ, CtWep1
- SLC to James M. Tuohy, 4 November 1899 · London, England · UCCL05699 CCamarSJ, CtWep1
- SLC to James M. Tuohy, 19 December 1899 · London, England · UCCL05719 CCamarSJ, CtWep1
- SLC to Unidentified, 28 April 1900 · London, England · UCCL08412 CCamarSJ
- Rudyard Kipling to SLC, 6 May 1901 · Rottingdean, England · UCLC33268 CCamarSJ
- SLC to OLC, 27 November 1901 · Riverdale, N.Y · UCCL10647 CCamarSJ
- SLC to OLC, 30 November 1901 · Riverdale, N.Y · UCCL10646 CCamarSJ
- SLC to Clara L. Clemens, Unknown date · Unknown place · UCCL10649 CCamarSJ
- SLC to Otis Skinner, 7 May 1906 · New York, N.Y · UCCL07438 CCamarSJ
- Samuel F. G. Whitaker to SLC, 4 July 1907 · UCLC37344 CCamarSJ
- SLC to William E. Benjamin, Unknown date, New York, N.Y · UCCL08741 CCamarSJ
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