Sources: WU-MU
- Samuel L. Clemens to Henry M. Crane, 20 May 1867 · New York, N.Y · UCCL02779
- Samuel L. Clemens to Elisha Bliss, Jr., 5 May 1868 · San Francisco, Calif · UCCL02731
- Samuel L. Clemens to Henry M. Crane, 3 September 1868 · Elmira, N.Y · UCCL02749
- Samuel L. Clemens to Elisha Bliss, Jr., 3 September 1868 · Elmira, N.Y · UCCL02748
- Samuel L. Clemens to Elisha Bliss, Jr., 15 August 1869 · Buffalo, N. Y · UCCL00333
- Samuel L. Clemens to Mathew B. Cox, 24 September 1869 · Buffalo, N.Y · UCCL10990
- Samuel L. Clemens to Frank Fuller, 26 April 1870 · Buffalo, N. Y · UCCL00460
- Samuel L. Clemens to Elisha Bliss, Jr., 5 May 1870 · Elmira, N.Y · UCCL00461
- Samuel L. Clemens to Elisha Bliss, Jr., 27 June 1870 · Elmira, N.Y · UCCL00483
- Samuel L. Clemens to James Redpath, 3 December 1870 · Buffalo, N.Y · UCCL00549
- Samuel L. Clemens to James Redpath and George L. Fall, 11 October 1871 · Hartford, Conn · UCCL00659
- Samuel L. Clemens to Elisha Bliss, Jr., 20 March 1872 · Elmira, N. Y · UCCL11848
- Samuel L. Clemens to Elisha Bliss, Jr., 3 May 1873 · Hartford, Conn · UCCL00912
- Samuel L. Clemens to Francis D. Finlay, 12 January 1874 · Liverpool, England · UCCL01040
- Samuel L. Clemens to Francis D. Finlay, 23 April 1874 · Elmira, N. Y · UCCL01078
- Samuel L. Clemens to William A. Seaver, 1 May 1874 · Elmira, N.Y · UCCL01081
- Samuel L. Clemens to William A. Seaver, 20 May 1874 · Elmira, N.Y · UCCL01090
- Samuel L. Clemens to Frank Fuller, 6 September 1874 · Elmira, N.Y · UCCL01124
- Samuel L. Clemens to William A. Seaver, 25 September 1874 · Hartford, Conn · UCCL01100
- Samuel L. Clemens to Francis D. Finlay, 10 November 1874 · Hartford, Conn · UCCL01146
- Samuel L. Clemens to William A. Seaver, 26 February 1875 · Hartford, Conn · UCCL01198
- Samuel L. Clemens to William A. Seaver, 6 March 1875 · Hartford, Conn · UCCL01204
- Samuel L. Clemens to William A. Seaver, 10 November 1875 · Hartford, Conn · UCCL07707
- Samuel L. Clemens to William A. Seaver, 5 December 1875 2nd of 2 · Hartford, Conn · UCCL01286
- Samuel L. Clemens to William A. Seaver, 16 September 1876 · Hartford, Conn · UCCL01365
- Samuel L. Clemens to Francis E. Bliss, 9 February 1879 · Munich, Germany · UCCL01629
- Samuel L. Clemens to Francis E. Bliss, 10 June 1879 · Paris, France · UCCL01664
- Samuel L. Clemens to Frank Fuller, 22 April 1880 · Hartford, Conn · UCCL01791
- Samuel L. Clemens to Francis E. Bliss, 23 October 1880 · Hartford, Conn · UCCL01844
- SLC to Francis E. Bliss, 30 May 1881 · Hartford, Conn · UCCL01960
- SLC to Frank Fuller, 5 July 1882 · Hartford, Conn · UCCL02231
- SLC to Francis E. Bliss, 9 September 1882 · Elmira, N.Y · UCCL02266
- SLC to Frank Fuller, 18 October 1884 · Hartford, Conn · UCCL03009
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