Sources: CCamarSJ
- Samuel L. Clemens to Emeline B. Beach, 5 December 1867 · Washington, D.C · UCCL00169
- Samuel L. Clemens to Emeline B. Beach, 8 January 1868 · Washington, D.C · UCCL00174
- SLC to OLC, 10–13 September 1869 · Unknown place · UCCL09405
- Samuel L. Clemens to Emeline B. Beach, 4 February 1874 · Hartford, Conn · UCCL01044
- SLC to OLC, 25 August 1881 · Boston, Mass · UCCL02015
- SLC to Susy (Olivia Susan) Clemens, 25 May 1882 · Hartford, Conn · UCCL09121
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