Sources: MoSW
- Samuel L. Clemens to John J. Murphy, 1 June 1869 · Elmira, N. Y · UCCL00310
- Samuel L. Clemens to Charles Henry Webb, 14 January 1871 · Buffalo, N.Y · UCCL00558
- Samuel L. Clemens to the Editor of Every Saturday (Thomas Bailey Aldrich), 15 January 1871 · Buffalo, N.Y · UCCL00559
- Samuel L. Clemens to John A. Lant, 28 September 1871 · Buffalo, N.Y · UCCL00655
- Samuel L. Clemens to Henry Lee, 8 October 1873 · London, England · UCCL00970
- Samuel L. Clemens to George H. Fitzgibbon, 9 December 1873 · London, England · UCCL00995
- Samuel L. Clemens to Frank Fuller, 31 January 1874 · Hartford, Conn · UCCL01041
- Samuel L. Clemens to Thomas Bailey Aldrich, 15 and 16 March 1874 · Hartford, Conn · UCCL01063
- Samuel L. Clemens to Annie W. Fuller, 7 April 1874 · Hartford, Conn · UCCL01071
- Samuel L. Clemens to Unidentified, 5 October 1875 · Hartford, Conn · UCCL01268
- Samuel L. Clemens to Frank Fuller, 5 April 1878 · New York, N.Y · UCCL01552
- Samuel L. Clemens to Robert M. Hooper, 12 May? 1879 · Paris, France · UCCL08942
- Samuel L. Clemens to Frank Fuller with a note to Thomas L. James, New York Postmaster, 18 November 1879· Hartford, Conn · UCCL01721
- Samuel L. Clemens to Charles Warren Stoddard, 17 June 1880 · Elmira, N.Y · UCCL01813
- Samuel L. Clemens to Frank Fuller, 2 October 1880 · Hartford, Conn · UCCL01835
- SLC to James R. Osgood, 8 December 1881 · Montreal, Canada · UCCL02112
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