Addressees: Fuller, Frank
- Samuel L. Clemens to Frank Fuller, 1 and 8 June 1867 · New York, N.Y · UCCL00136
- Samuel L. Clemens to Frank Fuller, 7 June 1867 · New York, N.Y · UCCL00135
- Samuel L. Clemens to Frank Fuller, 7 August 1867 · Naples, Italy · UCCL00142
- Samuel L. Clemens to Frank Fuller, 24 November 1867 · Washington, D.C · UCCL00158
- Samuel L. Clemens to Frank Fuller, 2 December 1867 · Washington, D.C · UCCL00167
- Samuel L. Clemens to Frank Fuller, 5 December 1867 · Washington, D.C · UCCL00170
- Samuel L. Clemens to Frank Fuller, 13 December 1867 · Washington, D.C · UCCL00173
- Samuel L. Clemens to Frank Fuller, 12 May 1868 · San Francisco, Calif · UCCL02782
- Samuel L. Clemens to Frank Fuller, 15 August 1868 · Hartford, Conn · UCCL02744
- Samuel L. Clemens to Frank Fuller, 24 September 1868 · St. Louis, Mo · UCCL02753
- Samuel L. Clemens to Frank Fuller, 5–30 October 1868 · Hartford, Conn · UCCL09079
- Samuel L. Clemens to Frank Fuller, 26 April 1870 · Buffalo, N. Y · UCCL00460
- Samuel L. Clemens to Frank Fuller, 21 May 1870 · Buffalo, N.Y · UCCL00466
- Samuel L. Clemens to Frank Fuller, 31 January 1874 · Hartford, Conn · UCCL01041
- SLC to Frank Fuller, 20 March 1874 · Hartford, Conn · UCCL12794
- Samuel L. Clemens to Frank Fuller, 8–10 July 1874 · Elmira, N.Y · UCCL01107
- Samuel L. Clemens to Frank Fuller, 6 September 1874 · Elmira, N.Y · UCCL01124
- SLC to Frank Fuller, 29 September 1874 · Hartford, Conn · UCCL12808
- Samuel L. Clemens to Frank Fuller, 5 April 1878 · New York, N.Y · UCCL01552
- Samuel L. Clemens to Frank Fuller, 20 August 1878 · Lucerne, Switzerland · UCCL02526
- Samuel L. Clemens to Frank Fuller with a note to Thomas L. James, New York Postmaster, 18 November 1879· Hartford, Conn · UCCL01721
- Samuel L. Clemens to Frank Fuller, 22 November 1879 · Hartford, Conn · UCCL01723
- Samuel L. Clemens to Frank Fuller, 26 November 1879 · Hartford, Conn · UCCL01747
- Samuel L. Clemens to Frank Fuller, 5 December 1879 · Hartford, Conn · UCCL01733
- Samuel L. Clemens to Frank Fuller, 19 December 1879 · Hartford, Conn · UCCL01742
- Samuel L. Clemens to Frank Fuller, 18 February 1880 · Hartford, Conn · UCCL13039
- Samuel L. Clemens to Frank Fuller, 24 February 1880 · Hartford, Conn · UCCL01762
- Samuel L. Clemens to Frank Fuller, April? 1880 · Hartford, Conn · UCCL11987
- Samuel L. Clemens to Frank Fuller, 22 April 1880 · Hartford, Conn · UCCL01791
- Samuel L. Clemens to Frank Fuller, 2 October 1880 · Hartford, Conn · UCCL01835
- Samuel L. Clemens to Frank Fuller per Telegraph Operator, 30 October 1880 · Hartford, Conn · UCCL01849
- SLC to Frank Fuller, 14 March 1882 · Hartford, Conn · UCCL03740
- SLC to Frank Fuller, 5 July 1882 · Hartford, Conn · UCCL02231
- SLC to Frank Fuller, 18 October 1884 · Hartford, Conn · UCCL03009
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