Sources: ODa2
- Samuel L. Clemens to Henry M. Crane, 7 October 1868 · Hartford, Conn · UCCL02740 ODa2
- Samuel L. Clemens to James Redpath per Telegraph Operator, 4 December 1869 · New York, N.Y · UCCL02445 ODa2
- Samuel L. Clemens to Adolph H. Sutro, 11 June 1872 · Hartford, Conn · UCCL00755 ODa2
- Samuel L. Clemens to Alfred Tennyson, 15 December 1873 · London, England · UCCL01006 ODa2
- Samuel L. Clemens to Tom Taylor, per Charles Warren Stoddard, 29 December 1873 · London, England · UCCL01019 ODa2
- Samuel L. Clemens to James Redpath, per Telegraph Operator, 3 March 1874 · Hartford, Conn · UCCL01060 ODa2
- Samuel L. Clemens to James Redpath, per Telegraph Operator, 13 March 1874 · Hartford, Conn · UCCL08722 ODa2
- Samuel L. Clemens to Herbert E. Hill, 3 November 1880 · Hartford, Conn · UCCL09943 ODa2
- Samuel L. Clemens to James R. Osgood, 13 December 1880 · Hartford, Conn · UCCL01871 ODa2
- SLC to Francis E. Bliss, 16 June 1881 · Branford, Conn · UCCL11208 ODa2
- SLC to Elisabeth N. Fairchild, 6 October 1881 · Hartford, Conn · UCCL02045 ODa2
- SLC to George William Curtis, 25 January 1882 · Hartford, Conn · UCCL09530 ODa2, CU-MARK
- SLC to Charles S. Fairchild, 20 June 1882 · Hartford, Conn · UCCL03243 ODa2
- SLC to Edwin Pond Parker, 14 May–31 May 1883 · Hartford, Conn · UCCL11190 ODa2
- SLC to OLC, Unknown date · Unknown place · UCCL11350 ODa2
- SLC to A. R. Reasoner, 1 December 1885 · New York, N.Y · UCCL10348 ODa2
- SLC to John R. Young, 7 December 1885 · Hartford, Conn · UCCL11207 ODa2
- SLC to Unidentified, 16 September 1886 · Elmira, N.Y · UCCL10442 ODa2
- SLC to William Smith, 3–4 February 1887 · Hartford, Conn · UCCL03522 ODa2, CBev6
- SLC to Lorettus S. Metcalf, 13 April 1888 · Hartford, Conn · UCCL03714 ODa2
- SLC to O. E. Dunlap, 19 June 1888 · Hartford, Conn · UCCL11206 ODa2
- SLC to Clarence C. Rice, 4 July 1888 · Elmira, N.Y · UCCL11191 ODa2
- SLC to Frederick J. Hall, 28 December 1890 · Hartford, Conn · UCCL11205 ODa2
- SLC to Edward W. Bok, 24 April 1891 · Hartford, Conn · UCCL04194 ODa2
- SLC to Elisabeth N. Fairchild, 8 March 1892 · Menton, France · UCCL04273 ODa2
- SLC to Henry M. Alden, 13 October 1892 · Florence, Italy · UCCL10567 ODa2
- SLC to Susan L. Warner, 30 April 1893 · New York, N.Y · UCCL11654 ODa2
- SLC to ? Parker, 31 December 1893 · New York, N.Y · UCCL09077 ODa2
- SLC to Mary Mapes Dodge, 21 January 1894 · New York, N.Y · UCCL04676 ODa2
- SLC to Henry H. Rogers, 22 August 1895 · Victoria, Canada · UCCL11201 ODa2
- SLC to Henry H. Rogers, 30 August 1895 · RMS Warrimoo, en route from Vancouver, Canada, to Honolulu, Hawaii · UCCL11199 ODa2
- SLC to Henry H. Rogers, 10 November 1895 · Timaru, New Zealand · UCCL11200 ODa2
- SLC to Henry H. Rogers, 12 December 1895 · Wellington, New Zealand · UCCL11202 ODa2
- SLC to J. Henry Harper, 5 December 1896 · London, England · UCCL09957 ODa2
- SLC to Henry Preston Child, July 1897 · Unknown place · UCCL11198 ODa2
- SLC to Ferdinand Gross, 10 October 1897 · Vienna, Austria · UCCL04708 ODa2
- SLC to Unidentified, May 1898 · Vienna or Kaltenleutgeben, Austria · UCCL11221 ODa2
- SLC to Edwin Pond Parker, 2 August 1898 · Kaltenleutgeben, Austria · UCCL05418 ODa2
- SLC to Eva L. Farrell, 12 November 1899 · London, England · UCCL05706 ODa2
- SLC to Alfred E. Ann, 20 February 1900 · London, England · UCCL08856 ODa2
- SLC to Elizabeth MacAlister, 7 July 1900 · London, England · UCCL09364 ODa2
- SLC to Chester S. Lord, 10 June 1902 · Riverdale, N.Y · UCCL06358 ODa2
- SLC to Charles S. Fairchild, 13 August 1902 · York Harbor, Me · UCCL06404 ODa2
- SLC to Henry L. Stoddard, 28 November 1902 · New York, N.Y · UCCL11218 ODa2
- SLC to Louise M. Sill, 26 December 1902 · New York, N.Y · UCCL11175 ODa2
- SLC to Charles S. Fairchild, 2 March 1903 · Riverdale, N.Y · UCCL06590 ODa2
- SLC to Livingston Wright, 17 April 1903 · Riverdale, N.Y · UCCL06623 ODa2
- SLC to Charles S. Fairchild, 14 May 1903 · Riverdale, N.Y · UCCL06659 ODa2
- SLC to Mary Mapes Dodge, 18 December 1903 · Florence, Italy · UCCL06770 ODa2
- SLC to Charles S. and Elisabeth N. Fairchild, 20 July 1904 · Lee, Mass · UCCL06891 ODa2, TxAu3
- SLC per Isabel V. Lyon to Samuel J. Elder, 21 June 1905 · Dublin, N.H · UCCL07067 ODa2
- SLC to Daisy Scott, 28 December 1905 · New York, N.Y · UCCL11222 ODa2
- SLC to Charles D. Reid, January 1906 · New York, N.Y · UCCL11186 ODa2
- SLC per Isabel V. Lyon to Alice M. Ditson, 5 March 1906 · New York, N.Y · UCCL11194 ODa2, CU-MARK
- SLC to Florence Watson Cadieu, 15 March 1906 · New York, N.Y · UCCL11188 ODa2
- SLC to Unidentified, 12 April 1906 · New York, N.Y · UCCL11211 ODa2
- SLC to Garth W. Cate, 25 November 1906 · New York, N.Y · UCCL11189 ODa2
- SLC to Anita Moffett, December 1906 · Unknown place · UCCL11187 ODa2
- SLC to George B. Harvey, 22 February 1907 · New York, N.Y · UCCL09982 ODa2
- SLC to I. Benjamin Stone, July 1907 · London, England · UCCL11316 ODa2
- SLC to Malcolm D. Graham, 25 May 1908 · New York, N.Y · UCCL10463 ODa2
- SLC to Jeannette Cholmeley-Jones, August 1908 · Redding, Conn · UCCL11217 ODa2
- SLC to Marguerite Schmitt, 24 September 1908 · Redding, Conn · UCCL09384 ODa2
- SLC to Marion S. Allen, 31 January 1910 · Hamilton, Bermuda · UCCL10382 ODa2
- SLC to Helen S. Allen, 31 January 1910 · Unknown place · UCCL10383 ODa2
- SLC to Helen S. Allen, 6 March and April 8-11? 1910 · Hamilton, Bermuda · UCCL09914 ODa2
- SLC to Julius G. Rathbun, 2 February n.y. · Hartford, Conn · UCCL11203 ODa2
- SLC to W. S. Walton, Unknown date · Unknown place · UCCL11185 ODa2
- SLC to Unidentified, Unknown date, Hartford, Conn · UCCL11184 ODa2
- SLC to Unidentified, Unknown date · Unknown place · UCCL11178 ODa2
- SLC to Unidentified, Unknown date · Unknown place · UCCL11177 ODa2
- SLC to Lucy A. Perkins, Unknown date, Hartford, Conn · UCCL11180 ODa2
- SLC to Isabel V. Lyon, Unknown date · Unknown place · UCCL11317 ODa2
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