Sources: ODa2
- Samuel L. Clemens to Henry M. Crane, 7 October 1868 · Hartford, Conn · UCCL02740
- Samuel L. Clemens to James Redpath per Telegraph Operator, 4 December 1869 · New York, N.Y · UCCL02445
- Samuel L. Clemens to Adolph H. Sutro, 11 June 1872 · Hartford, Conn · UCCL00755
- Samuel L. Clemens to Alfred Tennyson, 15 December 1873 · London, England · UCCL01006
- Samuel L. Clemens to Tom Taylor, per Charles Warren Stoddard, 29 December 1873 · London, England · UCCL01019
- Samuel L. Clemens to James Redpath, per Telegraph Operator, 3 March 1874 · Hartford, Conn · UCCL01060
- Samuel L. Clemens to James Redpath, per Telegraph Operator, 13 March 1874 · Hartford, Conn · UCCL08722
- Samuel L. Clemens to Herbert E. Hill, 3 November 1880 · Hartford, Conn · UCCL09943
- Samuel L. Clemens to James R. Osgood, 13 December 1880 · Hartford, Conn · UCCL01871
- SLC to Francis E. Bliss, 16 June 1881 · Branford, Conn · UCCL11208
- SLC to Elisabeth N. Fairchild, 6 October 1881 · Hartford, Conn · UCCL02045
- SLC to George William Curtis, 25 January 1882 · Hartford, Conn · UCCL09530
- SLC to Charles S. Fairchild, 20 June 1882 · Hartford, Conn · UCCL03243
- SLC to Edwin Pond Parker, 14 May–31 May 1883 · Hartford, Conn · UCCL11190
- SLC to OLC, Unknown date · Unknown place · UCCL11350
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