Addressees: Watterson, Henry
- Samuel L. Clemens to Henry Watterson, 29 May–15 June? 1873 · London, England · UCCL11801
- Samuel L. Clemens to Henry Watterson, 9 October 1874 · Hartford, Conn · UCCL01136
- Samuel L. Clemens to Henry Watterson, 8? November 1874 · Hartford, Conn · UCCL12054
- SLC to Henry Watterson, 18 August 1896 · London, England · UCCL05089
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