Sources: Axelrod
- Samuel L. Clemens to Henry Abbey, 21 August 1869 · Buffalo, N.Y · UCCL00337
- Samuel L. Clemens to Elisha Bliss, Jr., 28 December 1869 · New York, N. Y · UCCL00396
- Samuel L. Clemens to James Redpath, 9 October 1870 · Buffalo, N.Y · UCCL10496
- Samuel L. Clemens to Elisha Bliss, Jr., 26 October 1870 · Buffalo, N.Y · UCCL00514
- Samuel L. Clemens to Elisha Bliss, Jr., 24 January 1871 · Buffalo, N.Y · UCCL00562
- Samuel L. Clemens to Fannie Dennis, 17 February 1871 · Buffalo, N.Y · UCCL00578
- Samuel L. Clemens to James Redpath, 27 June 1871 · 2nd of 2 · Elmira, N.Y · UCCL00623
- Samuel L. Clemens to James Redpath, 27 June 1871 · 1st of 2 · Elmira, N.Y · UCCL00621
- Samuel L. Clemens to James Redpath, 19 July 1871 · Elmira, N.Y · UCCL10497
- Samuel L. Clemens to James Redpath, 22 September 1871 · Buffalo, N.Y · UCCL10498
- Samuel L. Clemens to James Redpath, 24 October 1871 · Washington, D.C · UCCL00666
- Samuel L. Clemens to James Redpath, 7 January 1872 · Wooster, Ohio · UCCL00710
- Samuel L. Clemens to Henry Lee, 4 October 1872 · London, England · UCCL00818
- Samuel L. Clemens to Unidentified, 18 October 1872 · London, England · UCCL11320
- Samuel L. Clemens to Henry Lee, 5 November 1872 · London, England · UCCL11069
- Samuel L. Clemens to James Gordon Bennett, Jr., 17 November 1875 · Hartford, Conn · UCCL10499
- Samuel L. Clemens to William Dean Howells, 1 January 1876 · Hartford, Conn · UCCL00849
- Samuel L. Clemens to William Wright (Dan De Quille), 7 March 1876 · Hartford, Conn · UCCL01312
- Samuel L. Clemens to William Wright (Dan De Quille), 26 March 1876 · Hartford, Conn · UCCL01318
- Samuel L. Clemens to Andrew Chatto, 25 April 1879 · Paris, France · UCCL01650
- Samuel L. Clemens to H. L. Joachimsen · 8 April 1880 · Hartford, Conn · UCCL10562
- Samuel L. Clemens to Unidentified, 21 May 1880 · Hartford, Conn · UCCL11603
- Samuel L. Clemens to James R. Osgood, 19 October 1880 · Hartford, Conn · UCCL10668
- Samuel L. Clemens to James R. Osgood, 16 December 1880 · Hartford, Conn · UCCL01873
- SLC to Stephen C. Massett, 7 October 1881 · Hartford, Conn · UCCL02047
- SLC to James R. Osgood, 24 October 1881 · Hartford, Conn · UCCL02061
- SLC to Unidentified, 19 February 1882 · Hartford, Conn · UCCL02160
- SLC to James R. Osgood, 11 June 1882 · Hartford, Conn · UCCL08975
- SLC to R. Christie, 4 July 1882 · Hartford, Conn · UCCL11608
- SLC to Unidentified, 19 December 1883 · Hartford, Conn · UCCL11346
- SLC to Charles R. Deacon and Clover Club, 3 January 1884 · Hartford, Conn · UCCL09948
- SLC to Unidentified, 14 January 1884 · Hartford, Conn · UCCL02575
- SLC to Josiah H. Gilbert, 25 February 1884 · Hartford, Conn · UCCL10563
- SLC to Lorenz Rohr, 12 May 1884 · Hartford, Conn · UCCL02975
- SLC to James B. Pond, 1 September 1884 · Elmira, N.Y · UCCL01446
- SLC to Henry C. Robinson, 15 September–16 September 1884 · Elmira, N.Y · UCCL11234
- SLC to Neil Burgess, 28 October 1884 · Hartford, Conn · UCCL10564
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