Sources: NNC
- Samuel L. Clemens to William P. Carpenter, 23 September 1869 · Buffalo, N.Y · UCCL00357 NNC
- Samuel L. Clemens to Moncure D. Conway, 22 September 1872 · 2nd of 2 · London, England · UCCL00811 NNC
- Samuel L. Clemens to Moncure D. Conway, 6 October 1872 · London, England · UCCL00821 NNC
- Samuel L. Clemens to Moncure D. Conway, 1 July 1873 · London, England · UCCL00940 NNC
- Olivia L. (Livy) and Samuel L. Clemens to Ellen D. Conway, 23‒24? November and 8 December 1873, Hartford, Conn., and London, England · UCCL13949 NNC
- Samuel L. Clemens to Moncure D. Conway, 18 October 1875 · Hartford, Conn · UCCL01270 NNC
- Samuel L. Clemens to Moncure D. Conway, 26 February 1876 · Hartford, Conn · UCCL01310 NNC
- Moncure D. Conway to SLC, 24 March 1876 · UCLC50412 NNC
- Samuel L. Clemens to Moncure D. Conway, 25 March 1876 · Hartford, Conn · UCCL01317 NNC
- Samuel L. Clemens to Moncure D. Conway, 9 April 1876 · Hartford, Conn · UCCL01320 NNC
- Samuel L. Clemens to Moncure D. Conway, 16 April 1876 · Hartford, Conn · UCCL01323 NNC
- Samuel L. Clemens to Moncure D. Conway, 5 May 1876 · Hartford, Conn · UCCL01332 NNC
- Samuel L. Clemens to Moncure D. Conway, 27 May 1876 · Hartford, Conn · UCCL01336 NNC
- Samuel L. Clemens to Moncure D. Conway, 4 July 1876 · Elmira, N.Y · UCCL01347 NNC
- Samuel L. Clemens to Moncure D. Conway, 24 July 1876 · Elmira, N.Y · UCCL01351 NNC
- Samuel L. Clemens to Ellen D. Conway, 28 October 1876 · Hartford, Conn · UCCL01383 NNC
- Samuel L. Clemens to Moncure D. Conway, 2 November 1876 · Hartford, Conn · UCCL01386 NNC
- Samuel L. Clemens to Moncure D. Conway per Fanny C. Hesse, 13 December 1876 · Hartford, Conn · UCCL01394 NNC
- Samuel L. Clemens to Moncure D. Conway per Fanny C. Hesse, 29 December 1876 · Hartford, Conn · UCCL01397 NNC
- Samuel L. Clemens to Moncure D. Conway, per Fanny C. Hesse, 1? January 1877 · Hartford, Conn · UCCL01396 NNC
- Samuel L. Clemens to Moncure D. Conway, per Fanny C. Hesse, 10 January 1877 · Hartford, Conn · UCCL01400 NNC
- Samuel L. Clemens to Moncure D. Conway, 6 August 1877 · Elmira, N.Y · UCCL01466 NNC
- Samuel L. Clemens to Moncure D. Conway, 21 December 1877 · Hartford, Conn · UCCL01515 NNC
- Samuel L. Clemens to Moncure D. Conway, 21 January 1878 · Hartford, Conn · UCCL01525 NNC
- Samuel L. Clemens to Moncure D. Conway, 2 June 1878 · Heidelberg, Germany · UCCL01566 NNC
- Samuel L. Clemens to Moncure D. Conway, 19 January 1880 · Elmira, N.Y · UCCL01754 NNC
- Samuel L. Clemens to Moncure D. Conway, 31 March 1880 · Hartford, Conn · UCCL01778 NNC
- Samuel L. Clemens to Moncure D. Conway, 20 and 21 April 1880 · Hartford, Conn · UCCL01787 NNC, NN-BGC
- Samuel L. Clemens to Moncure D. Conway, 1 May 1880 · Hartford, Conn · UCCL01797 NNC
- Samuel L. Clemens to Moncure D. Conway, 20 May 1880 · Hartford, Conn · UCCL01808 NNC
- Samuel L. Clemens to Moncure D. Conway, 17 August 1880 · Elmira, N.Y · UCCL01824 NNC
- Samuel L. Clemens to Moncure D. Conway, 8 October 1880 · Hartford, Conn · UCCL01838 NNC
- Samuel L. Clemens to Moncure D. Conway, 3 January 1881 · Hartford, Conn · UCCL01887 NNC
- SLC to Charles A. Dana, 19 July 1883 · Elmira, N.Y · UCCL08857 NNC
- SLC to Brander Matthews, 31 March 1885 · New York, N.Y · UCCL03200 NNC
- SLC to Brander Matthews, 8 December 1885 · Hartford, Conn · UCCL03328 NNC
- SLC to Ellen D. Conway, 5 December 1887 · Hartford, Conn · UCCL03674 NNC
- SLC to Edmund C. Stedman, 2 November 1888 · New York, N.Y · UCCL03825 NNC
- SLC to Webster (C. L.) & Co., 9 January 1889 · Hartford, Conn · UCCL03849 NNC
- C. L. Webster & Co. to SLC, 21 February 1890 · New York, N.Y. · UCLC44978 NNC
- SLC to Joseph H. Twichell, 22 or 23 February 1890 · Hartford, Conn · UCCL10777 NNC
- SLC to OLC, 25 November 1890 · Bryn Mawr, Pa · UCCL08631 NNC
- SLC to Cyprian A. Bridge, 23 December 1895 · Sydney, Australia · UCCL04984 NNC
- SLC to Edmund C. Stedman, 16 October 1896 · London, England · UCCL05130 NNC
- SLC to Brander Matthews, 26 July 1898 · Kaltenleutgeben, Austria · UCCL05414 NNC
- Theresa Feodrowna Ries to SLC, 3 October 1898 · Vienna, Austria · UCLC46210 NNC
- SLC to H. Q. Russ, 3 October 1898 · Kaltenleutgeben, Austria · UCCL05441 NNC
- SLC to Francis E. Bliss, 1 January 1899 · Vienna, Austria · UCCL05472 NNC
- SLC to E. Duncan Lucas, 11 November 1899 · London, England · UCCL05704 NNC
- SLC to Brander Matthews, 11 July 1900 · London, England · UCCL08824 NNC
- SLC to Brander Matthews, 25 July 1900 · London, England · UCCL05838 NNC
- SLC to Brander Matthews, 14 August 1900 · London, England · UCCL05850 NNC
- SLC to Mary B. Rogers, 25 October 1900 · New York, N.Y · UCCL05884 NNC
- SLC to Brander Matthews, 2 November 1900 · New York, N.Y · UCCL05896 NNC
- SLC to Brander Matthews, 6 November 1900 · New York, N.Y · UCCL05897 NNC
- SLC to John K. Bangs, 20 November 1900 · New York, N.Y · UCCL05911 NNC
- SLC to Brander Matthews, 21 February 1901 · New York, N.Y · UCCL06008 NNC
- SLC to Moncure D. Conway, 10 March 1901 · New York, N.Y · UCCL06017 NNC
- SLC to William W. Appleton and Henry C. Appleton, 30 July 1901 · Saranac Lake, N.Y · UCCL06101 NNC
- SLC to Brander Matthews, 1901, New York, N.Y · UCCL05947 NNC
- SLC to Brander Matthews, 7 January 1902 · Riverdale, N.Y · UCCL06223 NNC
- SLC to Unidentified, 16 September 1902 · York Harbor, Me · UCCL06433 NNC
- George B. Harvey to SLC, 31 December 1902 · New York, N.Y. · UCLC33654 NNC
- SLC to Brander Matthews, 4 May 1903 · Riverdale, N.Y · UCCL06644 NNC
- SLC to Brander Matthews, 8 May 1903 · Riverdale, N.Y · UCCL06651 NNC
- SLC to Frederick A. Duneka, 4 July 1903 · Elmira, N.Y · UCCL06691 NNC
- SLC to George B. Harvey, 26 November 1903 · Florence, Italy · UCCL06760 NNC
- SLC to Moncure D. Conway, 21 June 1904 · Florence, Italy · UCCL06845 NNC
- SLC to Brander Matthews, 21 June 1904 · Florence, Italy · UCCL07587 NNC
- SLC to Anne W. and Seth Low, 25 July 1904 · Lee, Mass · UCCL06902 NNC
- SLC to Michael Monahan, 28 January 1905 · New York, N.Y · UCCL06989 NNC
- SLC to Brander Matthews, 23 May 1905 · Dublin, N.H · UCCL07038 NNC
- SLC to Frederick A. Duneka, 9 October 1905 · Dublin, N.H · UCCL07170 NNC
- Harper & Brothers per SLC to SLC, 17 November 1905, New York, N.Y. · UCLC33866 NNC
- George Dewey to SLC, 22 November 1905 · Washington, D.C. · UCLC34816 NNC
- SLC to Seth Low, 6 December 1905 · New York, N.Y · UCCL07233 NNC
- SLC to Moncure D. Conway, 6 December 1905 · New York, N.Y · UCCL07234 NNC
- SLC to Brander Matthews, 24 June 1906 · Dublin, N.H · UCCL07467 NNC
- SLC to Mary B. Rogers, 4 August 1906 · Dublin, N.H · UCCL07490 NNC
- SLC to Mary B. Rogers, 14 August 1906 · Dublin, N.H · UCCL07499 NNC
- SLC to Mary B. Rogers, 25–28 August 1906 · Dublin, N.H · UCCL07504 NNC
- SLC to Mary B. Rogers, 6 September 1906 · Dublin, N.H · UCCL07509 NNC
- George B. Harvey to SLC, 7 September 1906 · New York, N.Y. · UCLC35577 NNC
- SLC to Mary B. Rogers, 7 or 8 September 1906 · Dublin, N.H · UCCL07522 NNC
- William M. Vander Weyde to SLC, 21 September 1906 · New York, N.Y. · UCLC35583 NNC
- SLC to Mary B. Rogers, 21–23 September 1906 · New York, N.Y · UCCL07528 NNC
- Lois Kellogg to SLC, 22 September 1906 · UCLC35586 NNC
- SLC to Brander Matthews, 3 October 1906 · Dublin, N.H · UCCL07536 NNC
- SLC to Mary B. Rogers, 12–17 October 1906 · Dublin, N.H · UCCL07544 NNC
- SLC to Mary B. Rogers, 16 October 1906 · Dublin, N.H · UCCL02377 NNC
- SLC to Mary B. Rogers, 22 October 1906 · New York, N.Y · UCCL07553 NNC
- SLC to Mary B. Rogers, 25 October 1906 · New York, N.Y · UCCL02390 NNC
- SLC to Mary B. Rogers, 2 November 1906 · New York, N.Y · UCCL07560 NNC
- SLC to Mary B. Rogers, 7 November 1906 · New York, N.Y · UCCL07562 NNC
- SLC to Mary B. Rogers, 19 November 1906 · New York, N.Y · UCCL07571 NNC
- SLC to Mary B. Rogers, 25 November 1906 · New York, N.Y · UCCL07575 NNC
- SLC to Mary B. Rogers, 26 November 1906 · New York, N.Y · UCCL07576 NNC
- SLC to Mary B. Rogers, 26 December 1906 · New York, N.Y · UCCL07598 NNC
- SLC to Mary B. Rogers, 1906 · Unknown place · UCCL02402 NNC
- SLC to Harper & Brothers, 17 April 1907 · New York, N.Y · UCCL02690 NNC, CU-MARK
- SLC to Mary B. Rogers, 6 May 1907 · New York, N.Y · UCCL02418 NNC
- SLC to Harry Rogers and Mary B. Rogers, 3 June 1907 · Tuxedo Park, N.Y · UCCL07682 NNC
- SLC to Dorothy Butes, 23 July 1907 · Tuxedo Park, N.Y · UCCL07702 NNC
- SLC to Mary B. Rogers, October 1907 · Tuxedo Park, N.Y · UCCL02431 NNC
- SLC to Mary B. Rogers, 7 October 1907 · New York, N.Y · UCCL02589 NNC
- SLC to Mary B. Rogers, 11 October 1907 · Tuxedo Park, N.Y · UCCL07852 NNC
- SLC to Mary B. Rogers, 21 November–29 November 1906 · New York, N.Y · UCCL07867 NNC
- SLC to Mary B. Rogers, 7 February 1908 · New York, N.Y · UCCL02415 NNC
- SLC to Dorothy Sturgis, 13 April–14 April 1908 · New York, N.Y · UCCL07973 NNC
- SLC to Dorothy Sturgis, 19 April 1908 · New York, N.Y · UCCL07981 NNC
- SLC to Dorothy Sturgis, 25 April 1908 · New York, N.Y · UCCL07982 NNC
- SLC to Dorothy Sturgis, 9 May 1908 · New York, N.Y · UCCL07994 NNC
- SLC to Dorothy Sturgis, 15 May 1908 · New York, N.Y · UCCL08000 NNC
- SLC to Dorothy Sturgis, 24 May 1908 · New York, N.Y · UCCL08008 NNC
- SLC to Dorothy Sturgis, 2 June 1908 · New York, N.Y · UCCL08014 NNC
- SLC to Dorothy Sturgis, 7 June 1908 · New York, N.Y · UCCL08026 NNC
- SLC to Dorothy Sturgis, 14 June 1908 · New York, N.Y · UCCL08029 NNC
- SLC to Mary B. Rogers, 15 June 1908 · New York, N.Y · UCCL08030 NNC
- SLC to Mary B. Rogers, 19 June 1908 · Redding, Conn · UCCL08033 NNC
- SLC to Dorothy Sturgis, 5 July–14 July 1908 · Redding, Conn · UCCL08048 NNC
- SLC to Mary B. Rogers, 13 July 1908 · Redding, Conn · UCCL08068 NNC
- SLC to Dorothy Sturgis, 3 August 1908 · Redding, Conn · UCCL08073 NNC
- SLC to Dorothy Sturgis, 15 August 1908 · Redding, Conn · UCCL08087 NNC
- SLC to Mary B. Rogers, 17 August 1908 · Redding, Conn · UCCL08069 NNC
- SLC to Dorothy Sturgis, 30 September 1908 · Redding, Conn · UCCL08113 NNC
- SLC to Dorothy Sturgis, 27 October 1908 · Redding, Conn · UCCL08146 NNC
- SLC to Dorothy Sturgis, 6 December 1908 · Redding, Conn · UCCL08170 NNC
- SLC to Dorothy Sturgis, 26 December 1908 · Redding, Conn · UCCL08189 NNC
- SLC to Brander Matthews, Unknown date, New York, N.Y · UCCL07907 NNC
- SLC to Dorothy Sturgis, 31 January 1909 · Redding, Conn · UCCL08337 NNC
- SLC to Dorothy Sturgis, 3 March 1909 · Redding, Conn · UCCL08361 NNC
- SLC to Mary B. Rogers, 8 March–9 March 1909 · Redding, Conn · UCCL08368 NNC
- SLC to Frederick A. Duneka, 27 October 1909 · Redding, Conn · UCCL08476 NNC
- SLC to Mary B. Rogers, 29 December 1909 · Redding, Conn · UCCL08529 NNC
- SLC to Mary B. Rogers, 21 February 1910 · Hamilton, Bermuda · UCCL08562 NNC
- SLC to Edward M. Bunce, Unknown date, Hartford, Conn · UCCL08700 NNC
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