Sources: DLC
- SLC to Anson Burlingame or Edward L. Burlingame, 7 July 1866 · Honolulu, Hawaii · UCCL10786
- Samuel L. Clemens to John Russell Young, 22 November 1867 · Washington, D.C · UCCL00157
- Samuel L. Clemens to John Russell Young, 24 November 1867 · Washington, D.C · UCCL00159
- Samuel L. Clemens to John Russell Young, 25 November 1867 · Washington, D.C · UCCL00161
- Samuel L. Clemens to John Russell Young, 1 December 1867 · Washington, D.C · UCCL00164
- Samuel L. Clemens to John Russell Young, 4 December 1867 · Washington, D.C · UCCL00168
- Samuel L. Clemens to Charles John Russell Young, 1 February 1868 · Washington, D.C · UCCL00188
- Samuel L. Clemens to Anson Burlingame, 19 February 1868 · Washington, D.C · UCCL00195
- Samuel L. Clemens to John Russell Young, 8–10 March 1869 · Hartford, Conn · UCCL00270
- Samuel L. Clemens to Whitelaw Reid, 15 June 1869 · New York, N.Y · UCCL00317
- Samuel L. Clemens to Whitelaw Reid, 26 June 1869 · Elmira, N. Y · UCCL00323
- Samuel L. Clemens to Whitelaw Reid, 15 August 1869 · Buffalo, N. Y · UCCL00334
- Samuel L. Clemens to Whitelaw Reid, 7 September 1869 · Buffalo, N.Y · UCCL00350
- Samuel L. Clemens to Oliver Wendell Holmes, 30 September 1869 · Buffalo, N.Y · UCCL00360
- Samuel L. Clemens to Ainsworth R. Spofford, 10? October 1870 · Buffalo, N.Y · UCCL00507
- Samuel L. Clemens to Whitelaw Reid, 8 November 1870 · Buffalo, N.Y · UCCL00529
- Samuel L. Clemens to Whitelaw Reid, 26 December 1870 · Buffalo, N.Y · UCCL02791
- Samuel L. Clemens to Whitelaw Reid, 31 December 1870 · Buffalo, N.Y · UCCL02793
- Samuel L. Clemens to Whitelaw Reid, 22 February 1871 · Buffalo, N.Y · UCCL00581
- Samuel L. Clemens to Whitelaw Reid, 29 April 1871 · Elmira, N.Y · UCCL00607
- Samuel L. Clemens to Whitelaw Reid, 27 June 1871 · Elmira, N.Y · UCCL00624
- Samuel L. Clemens to James Redpath, 10 July 1871 (2nd of 3) · Elmira, N.Y · UCCL00635
- Samuel L. Clemens to Louise Chandler Moulton, 18 June 1872 · Hartford, Conn · UCCL00757
- Samuel L. Clemens to Whitelaw Reid, 3 January 1873 · 2nd of 2 · Hartford, Conn · UCCL00852
- Samuel L. Clemens to Whitelaw Reid per Telegraph Operator, 3 January 1873 · 1st of 2 · Hartford, Conn · UCCL00851
- Samuel L. Clemens to Whitelaw Reid per Telegraph Operator, 6 January 1873 · Hartford, Conn · UCCL00853
- Samuel L. Clemens to Whitelaw Reid, 13 and 17 January 1873 · Hartford, Conn · UCCL00857
- Samuel L. Clemens to Whitelaw Reid, 25 January 1873 · Hartford, Conn · UCCL00865
- Samuel L. Clemens to Whitelaw Reid, per Telegraph Operator, 1 February 1873 · Hartford, Conn · UCCL00871
- Samuel L. Clemens to Whitelaw Reid, 18 February 1873 · Hartford, Conn · UCCL00874
- Samuel L. Clemens to Whitelaw Reid, per Telegraph Operator, 7 March 1873 · 1st of 2 · Hartford, Conn · UCCL00882
- Samuel L. Clemens to Whitelaw Reid, 7 March 1873 · 2nd of 2 · Hartford, Conn · UCCL00883
- Samuel L. Clemens to Whitelaw Reid, 28 March 1873 · Hartford, Conn · UCCL00892
- Samuel L. Clemens to Whitelaw Reid, 17? April 1873 · Hartford, Conn · UCCL00902
- Samuel L. Clemens to Whitelaw Reid, 20 April 1873 · Hartford, Conn · UCCL00903
- Samuel L. Clemens and Charles Dudley Warner to Ainsworth R. Spofford, 21 April 1873 · Hartford, Conn · UCCL00904
- Samuel L. Clemens to Whitelaw Reid, 22 April 1873 · Hartford, Conn · UCCL00907
- Samuel L. Clemens to Whitelaw Reid, 22 April 1873 · Hartford, Conn · UCCL00906
- Samuel L. Clemens to Whitelaw Reid, 22 April 1873 · Hartford, Conn · UCCL00905
- Samuel L. Clemens to John Russell Young, 6 or 7 January 1874 · London, England · UCCL01016
- Samuel L. Clemens to Louise Chandler Moulton, 13 February 1874 · Hartford, Conn · UCCL01049
- Samuel L. Clemens to Thomas Bailey Aldrich, 24 March 1874 · Hartford, Conn · UCCL01068
- Samuel L. Clemens to Ainsworth R. Spofford, 7 May 1874 · Elmira, N.Y · UCCL01084
- Samuel L. Clemens to Ainsworth R. Spofford, 21 May 1874 · Elmira, N.Y · UCCL01092
- Samuel L. Clemens to Anna E. Dickinson, 28 June 1874 · Elmira, N.Y · UCCL01104
- Samuel L. Clemens to Thomas Bailey Aldrich, 8 July 1874 · Elmira, N. Y · UCCL01108
- Samuel L. Clemens to Anna E. Dickinson, 8–10 July 1874 · Elmira, N. Y · UCCL01106
- Samuel L. Clemens to Henry Watterson, 9 October 1874 · Hartford, Conn · UCCL01136
- Samuel L. Clemens to Louise Chandler Moulton, 14 October 1874 · Hartford, Conn · UCCL01139
- Samuel L. Clemens to Louise Chandler Moulton, 8 January 1875 · Hartford, Conn · UCCL01176
- Samuel L. Clemens to Ainsworth R. Spofford, 16 February 1875 · Hartford, Conn · UCCL01194
- Samuel L. Clemens to James G. Blaine, 11 October 1875 · Hartford, Conn · UCCL00552
- Samuel L. Clemens to Ainsworth R. Spofford, 23 October 1876 · Hartford, Conn · UCCL02467
- Samuel L. Clemens to Ainsworth R. Spofford, 18 July 1877 · Hartford, Conn · UCCL12308
- Samuel L. Clemens to Richard Whiteing, 17 May 1879 · Paris, France · UCCL01656
- Samuel L. Clemens to Thomas Bailey Aldrich, 25 May 1879 · Paris, France · UCCL01658
- Samuel L. Clemens to Elizabeth S. Stevens, 12 June 1879 · Paris, France · UCCL01667
- Samuel L. Clemens to Ainsworth R. Spofford, 26 September 1879 · Elmira, N.Y · UCCL01693
- Samuel L. Clemens to Ainsworth R. Spofford, 11 March 1880 · Hartford, Conn · UCCL01770
- SLC to John R. Young, 21 February 1881 · Hartford, Conn · UCCL01913
- SLC to John R. Young, 8 April 1881 · Hartford, Conn · UCCL02412
- SLC to John R. Young, 29 April 1881 · Hartford, Conn · UCCL01941
- SLC to John Esten Cooke, 17 August 1881 · Elmira, N.Y · UCCL02010
- SLC to John R. Young, 9 January 1882 · Hartford, Conn · UCCL02146
- SLC to John R. Young, 3 February 1882 · Hartford, Conn · UCCL02156
- SLC to John R. Young, 6 March 1882 · Hartford, Conn · UCCL02170
- SLC to John R. Young, 13 March 1882 · Hartford, Conn · UCCL02171
- SLC to John R. Young, 20 March 1882 · Hartford, Conn · UCCL02175
- SLC to John R. Young, 25 April 1882 · Arkansas City, Ark · UCCL02207
- Samuel L. Clemens to Ainsworth R. Spofford, 3 June 1882 · Hartford, Conn · UCCL13099
- SLC to Benjamin H. Ticknor, 14 March 1883 · Hartford, Conn · UCCL11153
- SLC to Ainsworth R. Spofford, 28 February 1884 · Hartford, Conn · UCCL02924
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