Addressees: Howland, Louise A
- Samuel L. Clemens to Robert M. and Louise M. Howland with a note to James W. Nye, 6 March 1870 · Buffalo, N.Y · UCCL00440 CU-MARK
- Samuel L. Clemens to Robert M. and Louise M. Howland, 6 April 1871 · Elmira, N.Y · UCCL00600 CU-MARK
- Olivia L. and Samuel L. Clemens to Louise A. and Robert M. Howland, 3? September 1877 · Elmira, N.Y · UCCL04656 CU-MARK
- SLC to Louise A. Howland, 23 January 1883 · Hartford, Conn · UCCL02339 CU-MARK
- SLC to Louise A. Howland, 31 January 1890 · Hartford, Conn · UCCL04009 CU-MARK
- SLC to Louise A. Howland, 16–31 December 1905 · New York, N.Y · UCCL07244 CU-MARK
- SLC to Louise A. Howland, 19 December 1905 · New York, N.Y · UCCL07265 CU-MARK
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