Sources: NvU
- SLC to Unidentified, December 1869 · Unknown place · UCCL10674
- Samuel L. Clemens to Francis E. Bliss, 25 April 1872 · Elmira, N.Y · UCCL09424
- SLC to OLC, December 1874 · Hartford, Conn · UCCL09710
- SLC to Moncure D. Conway, 5 February 1882 · Hartford, Conn · UCCL02157
- SLC to Frederick J. Hall, 21 December 1890 · Hartford, Conn · UCCL04003
- SLC to Unidentified, 24 April 1900 · London, England · UCCL05798
- SLC to Unidentified, 9 October 1902 · York Harbor, Me · UCCL08867
1