Sources: CtHMTH
- Samuel L. Clemens to Frank Fuller, 1 and 8 June 1867 · New York, N.Y · UCCL00136
- Samuel L. Clemens to Samuel E. Moffett, 1–2 October 1867 · SS Quaker City en route from Jaffa, Syria, to Alexandria, Egypt · UCCL00154
- Samuel L. Clemens to Samuel Williams, 14 April 1868 · San Francisco, Calif · UCCL02781
- Samuel L. Clemens to Jervis Langdon, 2 December 1868 · New York, N.Y · UCCL02772
- Samuel L. Clemens to Stephen C. Massett (Jeems Pipes), 2 September 1869 · Buffalo, N.Y · UCCL00218
- Samuel L. Clemens to Henry M. Crane, 3 September 1869 · Buffalo, N.Y · UCCL00345
- Samuel L. Clemens to John H. Gourlie, Jr., 7 September 1869 · Buffalo, N.Y · UCCL10500
- Samuel L. and Olivia L. Clemens to Jervis and Olivia Lewis Langdon, 9 February 1870 · Buffalo, N.Y · UCCL00423
- Samuel L. and Olivia L. Clemens to Olivia Lewis Langdon, 20 February 1870 · Buffalo, N.Y · UCCL00430
- Olivia L. and Samuel L. Clemens to Jervis Langdon, 26 February 1870 · Buffalo, N.Y · UCCL00433
- Samuel L. and Olivia L. Clemens to Jervis Langdon, 2 and 3 March 1870 · Buffalo, N.Y · UCCL00437
- Samuel L. and Olivia L. Clemens to Jervis and Olivia Lewis Langdon, 27 March 1870 · Buffalo, N. Y · UCCL00450
- Olivia L. and Samuel L. Clemens to Susan L. Crane, 16 April 1870 · Buffalo, N.Y · UCCL00454
- Samuel L. and Olivia L. Clemens to Jervis and Olivia Lewis Langdon, 16 and 17 April 1870 · Buffalo, N.Y · UCCL00455
- Samuel L. and Olivia L. Clemens to Theodore W. Crane, 22 April 1870 · Buffalo, N. Y · UCCL00458
- Samuel L. Clemens to Mary Janney, 4 May 1870? · Elmira, N.Y · UCCL08531
- Olivia L. and Samuel L. Clemens to Jervis Langdon, 13 May 1870 · Buffalo, N.Y · UCCL00464
- Samuel L. Clemens to Jervis Langdon, 22 May 1870 · Buffalo, N.Y · UCCL00469
- Samuel L. Clemens to Elisha Bliss, Jr., 9 June 1870 · Elmira, N.Y · UCCL00478
- Samuel L. Clemens to Daniel Slote, 27 June 1870 · Elmira, N.Y · UCCL00484
- Samuel L. Clemens to Francis E. Bliss and Frances T. French, 15 September 1870 · Buffalo, N.Y · UCCL00505
- Samuel L. Clemens to Franklin D. Locke, 24 September 1870 · Buffalo, N.Y · UCCL00432
- Samuel L. Clemens to Olivia Lewis Langdon, per Telegraph Operator, 7 November 1870 · Buffalo, N.Y · UCCL00526
- Samuel L. Clemens to Olivia Lewis Langdon, 11? November 1870 · Buffalo, N.Y · UCCL08958
- Samuel L. Clemens to Eunice Ford, 11 November 1870 · Buffalo, N.Y · UCCL00530
- Samuel L. Clemens to Olivia Lewis Langdon, 19 November 1870 · Buffalo, N.Y · UCCL00539
- Samuel L. Clemens to Charles J. Langdon, 20 November 1870 · Buffalo, N.Y · UCCL00541
- Samuel L. Clemens to Eunice Ford, 25? December 1870 · Buffalo, N.Y · UCCL02787
- Samuel L. Clemens to Samuel S. Cox, 9 March 1871 · Buffalo, N.Y · UCCL11006
- Samuel L. Clemens to Unidentified, 18 April 1871 · Elmira, N.Y · UCCL11014
- Samuel L. Clemens to James Redpath, 9 October 1871 · Hartford, Conn · UCCL00657
- Samuel L. Clemens to Charles E. Perkins, 8 May 1872 · Elmira, N.Y · UCCL00745
- Samuel L. Clemens to Olivia Susan (Susy) Clemens, 9 May 1872 · Cleveland, Ohio · UCCL00746
- Samuel L. Clemens to George H. Fitzgibbon, 5 October 1872 · London, England · UCCL00820
- Samuel L. Clemens to William A. Turner, 3 November 1872 · London, England · UCCL00827
- Samuel L. Clemens to Olivia Lewis Langdon, 3 December 1872 · Hartford, Conn · UCCL00838
- Olivia L. and Samuel L. Clemens to Olivia Lewis Langdon, 17 February 1873 · Hartford, Conn · UCCL00879
- Samuel L. Clemens to Charles F. Wingate, 2 April 1873 · Hartford, Conn · UCCL00896
- Olivia L. and Samuel L. Clemens to Olivia Lewis Langdon, 17 May 1873 · SS Batavia at New York, N.Y · UCCL00916
- Olivia L. and Samuel L. Clemens to Olivia Lewis Langdon, 2 and 6 August 1873 · Edinburgh, Scotland · UCCL00959
- Samuel L. Clemens to Unidentified, 11 October 1873 · London, England · UCCL00971
- Samuel L. Clemens to Olivia Lewis Langdon, 12 October 1873 · London, England · UCCL00973
- Samuel L. Clemens to George H. Fitzgibbon, 28 November 1873 · London, England · UCCL00990
- Samuel L. Clemens to George H. Fitzgibbon, 1 January 1874 · London, England · UCCL01027
- Samuel L. Clemens to George H. Fitzgibbon, 6 January 1874 · London, England · UCCL01035
- Samuel L. Clemens to the Superintendent of the American Asylum for Deaf and Dumb, 23 February 1874 · Hartford, Conn · UCCL10587
- Samuel L. Clemens to Charles E. Perkins, 8 May 1874 · Elmira, N.Y · UCCL01085
- Olivia L. and Samuel L. Clemens to Charles J. Langdon, 28? November 1874 · Hartford, Conn · UCCL01156
- Olivia L. and Samuel L. Clemens to Olivia Lewis Langdon, 14 March 1875 · Hartford, Conn · UCCL01207
- Samuel L. Clemens to John T. Raymond, 12 May 1875 · Hartford, Conn · UCCL01233
- Samuel L. Clemens to John T. Raymond, 13 May 1875 · Hartford, Conn · UCCL01234
- Samuel L. Clemens to Mr. Gerard, 6 July 1875 · Hartford, Conn · UCCL01246
- Samuel L. Clemens to Charles E. Perkins, 24 or 25 August? 1875 · Newport, R.I · UCCL01382
- Samuel L. Clemens to Olivia Lewis Langdon, 22 December 1875 · Hartford, Conn · UCCL01288
- Samuel L. Clemens to Jerome B. Stillson, 19 January 1876 · Hartford, Conn · UCCL01301
- Samuel L. Clemens to Montgomery Schuyler, 30 July 1876 · Elmira, N.Y · UCCL11917
- Samuel L. Clemens to Charles E. Perkins, 5 October 1876 · Hartford, Conn · UCCL01370
- Samuel L. Clemens to Charles E. Perkins, 16 October 1876 · Hartford, Conn · UCCL01376
- Samuel L. Clemens to Charles E. Perkins, 20 October 1876 · Hartford, Conn · UCCL01378
- Samuel L. Clemens to John T. Raymond, 27 October 1876 · Hartford, Conn · UCCL01381
- Samuel L. Clemens to Charles E. Perkins, 11 December 1876 · Hartford, Conn · UCCL01393
- Samuel L. Clemens to Charles E. Perkins, 20 December 1876 · Hartford, Conn · UCCL01395
- Samuel L. Clemens to Hjalmar H. Boyesen, 17 January 1877 · Hartford, Conn · UCCL12673
- Samuel L. Clemens to Charles E. Perkins, 22 January 1877 · Hartford, Conn · UCCL01402
- Olivia L. and Samuel L. Clemens to Olivia Lewis Langdon, 2 and 4 February 1877 · Hartford, Conn · UCCL01405
- Samuel L. Clemens to Charles E. Perkins, 26 April 1877 · Baltimore, Md · UCCL01417
- Samuel L. Clemens to Charles E. Perkins, 4–16 May 1877 · Hartford, Conn · UCCL01423
- Samuel L. Clemens to the American Publishing Company, 12 May 1877 · Hartford, Conn · UCCL01429
- Samuel L. Clemens to George P. Bissell and Company, per Charles E. Perkins, 15 May 1877 · Hartford, Conn · UCCL01431
- Samuel L. Clemens to Charles E. Perkins, 15 May 1877 · Hartford, Conn · UCCL01432
- Samuel L. Clemens to Henry Wadsworth Longfellow, 4 June 1877 · Hartford, Conn · UCCL01438
- Samuel L. Clemens to Charles E. Perkins, 12 June 1877 · Elmira, N.Y · UCCL01440
- Samuel L. Clemens to Charles E. Perkins, 4 July 1877 · Elmira, N.Y · UCCL01445
- Samuel L. Clemens to Charles E. Perkins, per Telegraph Operator, 7 July 1877 · Elmira, N.Y · UCCL01447
- Samuel L. Clemens to Charles E. Perkins, 7 July 1877 · Elmira, N.Y · UCCL01448
- Samuel L. Clemens to George M. Fenn, 2 August 1877 · Hartford, Conn · UCCL02366
- Samuel L. Clemens to Charles E. Perkins, 3 August 1877 · 2nd of 2 · Elmira, N.Y · UCCL01464
- Samuel L. Clemens to Charles E. Perkins, 3 August 1877 · 1st of 2 · Elmira, N.Y · UCCL01463
- Samuel L. Clemens to Charles E. Perkins, 11 August 1877 · Elmira, N.Y · UCCL01469
- Samuel L. Clemens to Charles E. Perkins, 18? August 1877 · Elmira, N.Y · UCCL01472
- Samuel L. Clemens to John T. Lewis, 24 August 1877 · Elmira, N.Y. · 2nd of 2 · UCCL09282
- Samuel L. Clemens to Charles E. Perkins, 20 September 1877 · Hartford, Conn · UCCL01485
- Samuel L. Clemens to Charles E. Perkins, 21 September 1877 · Hartford, Conn · UCCL01486
- Samuel L. Clemens to Charles E. Perkins, 24 September 1877 · Hartford, Conn · UCCL01488
- Samuel L. Clemens to Matthew H. Bartlett, October 1877 · 1st of 2 · Hartford, Conn · UCCL09280
- Samuel L. Clemens to Charles E. Perkins, 3? October 1877 · Hartford, Conn · UCCL01489
- Samuel L. Clemens to Charles E. Perkins, 4 October 1877 · Hartford, Conn · UCCL01491
- Samuel L. Clemens to Charles E. Perkins, 5 or 6 October 1877 · Hartford, Conn · UCCL01492
- Samuel L. Clemens to Charles E. Perkins, 14 October 1877 · Hartford, Conn · UCCL01494
- Samuel L. Clemens to Charles E. Perkins, 18 October 1877 · Hartford, Conn · UCCL01497
- Samuel L. Clemens to Charles E. Perkins, 20? October 1877 · Hartford, Conn · UCCL03233
- Samuel L. Clemens to Olivia Lewis Langdon, 5 December 1877 · Hartford, Conn · UCCL01509
- Samuel L. Clemens to Charles E. Perkins, 28 December 1877 · Hartford, Conn · UCCL01521
- SLC to Kate V. Austin, 12 January 1878 · Elmira, N.Y · UCCL01523
- Samuel L. Clemens to Frank W. Cheney, 24 February 1878 · Hartford, Conn · UCCL01534
- Samuel L. Clemens to John T. Raymond per Charles E. Perkins, 16 March 1878 · Hartford, Conn · UCCL01545
- Samuel L. Clemens to Olivia Lewis Langdon, 20 April 1878 · SS Holsatia en route from New York, N.Y., to Hamburg, Germany · UCCL01556
- Samuel L. Clemens to Joseph H. Twichell and George P. Bissell, 23 May 1878 · Heidelberg, Germany · UCCL10474
- Samuel L. Clemens to Olivia Lewis Langdon, 13 September 1878 · Geneva, Switzerland · UCCL01595
- Samuel L. Clemens to Unidentified, 3 November 1878 · Rome, Italy · UCCL01604
- Samuel L. Clemens to Unidentified, 20 November 1878 · Munich, Germany · UCCL12218
- Samuel L. Clemens to Olivia Lewis Langdon, 2 December 1878 · Munich, Germany · UCCL01611
- Olivia L. and Olivia Susan (Susy) Clemens per Olivia L. and Samuel L. Clemens to Olivia Lewis Langdon, 8 December 1878 · Munich, Germany · UCCL01612
- Samuel L. Clemens to Olivia Lewis Langdon, 26? December 1878 · Munich, Germany · UCCL01617
- Olivia L. and Samuel L. Clemens to Olivia Lewis Langdon, 19 January 1879 · Munich, Germany · UCCL01621
- Samuel L. Clemens to Orion Clemens, 9 February 1879 · Munich, Germany · UCCL01631
- Samuel L. Clemens to Olivia Lewis Langdon, 23 February 1879 · Munich, Germany · UCCL01635
- Samuel L. Clemens, Olivia Susan (Susy) Clemens (per Samuel L. Clemens), and Olivia L. Clemens to Olivia Lewis Langdon, 30 March 1879 · Paris, France · UCCL01645
- Samuel L. Clemens to Charles J. Langdon, 17 June 1879 · Paris, France · UCCL01673
- Samuel L. Clemens to Charles E. Perkins, 1–31 July 1879 · Unknown place · UCCL09843
- Samuel L. Clemens to Charles E. Perkins, 9 September 1879 · Elmira, N.Y · UCCL01688
- Samuel L. Clemens to Frederick Schweppe, 13 October 1879 · Elmira, N.Y · UCCL01698
- Samuel L. Clemens to Pierre D. Peltier, 14 October 1879 · Elmira, N.Y · UCCL01699
- Samuel L. Clemens to Olivia L. Clemens, 11 November 1879 (2nd of 2)· Chicago, Ill · UCCL01713
- Samuel L. Clemens to Charles H. Clark, 6 March 1880 · Hartford, Conn · UCCL08597
- Samuel L. Clemens to Charles H. Phelps, 8 April 1880 · Hartford, Conn · UCCL12483
- Samuel L. Clemens to Harriet E. Whitmore, 11 April 1880 · Hartford, Conn · UCCL11264
- Samuel L. Clemens to Franklin G. Whitmore, 18 May 1880 · Hartford, Conn · UCCL01807
- Samuel L. Clemens for Jean Clemens to Olivia Lewis Langdon, 19 August 1880 · Elmira, N.Y · UCCL01826
- Samuel L. Clemens to George Griffin, per Telegraph Operator, 11 September 1880 · Elmira, N.Y · UCCL01830
- Samuel L. Clemens to Harriet E. Whitmore, 13 September 1880 · Elmira, N.Y · UCCL01832
- Samuel L. Clemens to Charles E. Perkins, 15? September 1880 · Elmira, N.Y · UCCL01831
- Samuel L. Clemens to Charles E. Perkins, 23 September 1880 · Elmira, N.Y · UCCL08623
- Samuel L. Clemens to Charles E. Perkins, 25 October 1880 · Hartford, Conn · UCCL01846
- Samuel L. Clemens to the Editor of the New York Evening Post, 23 November 1880 · Hartford, Conn · UCCL12212
- SLC to Charles E. Perkins, 3 February 1881 · Hartford, Conn · UCCL01904
- SLC to Charles E. Perkins, 25 February 1881 · Hartford, Conn · UCCL01915
- SLC to Karl Gerhardt, 27 February 1881 · Hartford, Conn · UCCL12674
- SLC to Unidentified, 5 March 1881 · Unknown place · UCCL11008
- SLC to Francis E. Bliss, 8 April 1881 · Hartford, Conn · UCCL02414
- SLC to Charles E. Perkins, 2 July 1881 · Branford, Conn · UCCL01981
- SLC to Osgood (J.R.) & Co., 6 August 1881 · Elmira, N.Y · UCCL09234
- SLC to Franklin G. Whitmore, 8 August 1881 · Elmira, N.Y · UCCL01996
- SLC to Franklin G. Whitmore, 18 August 1881 · Elmira, N.Y · UCCL09007
- SLC to Karl Gerhardt and Hattie J. Gerhardt, 31 August 1881 · Elmira, N.Y · UCCL12693
- SLC to Franklin G. Whitmore, 3 September 1881 · Elmira, N.Y · UCCL02024
- SLC to H. M. Lawrence per Charles L. Webster and Cable Operator, 4 September 1881 · Elmira, N.Y · UCCL01951
- SLC to Charles S. Fairchild, 22 September 1881 · Hartford, Conn · UCCL02278
- SLC to Benjamin H. Ticknor, 10 October 1881 · Hartford, Conn · UCCL12678
- SLC to Charles E. Perkins, 12 December 1881 · Hartford, Conn · UCCL01739
- SLC to Robert J. Burdette, 20 December 1881 · Hartford, Conn · UCCL09317
- SLC to Unidentified, 23 December 1881 · Hartford, Conn · UCCL11009
- SLC to Harriet E. Whitmore, July 1882 · Hartford, Conn · UCCL09322
- SLC to Ellen C. Taft, July 1882 · Hartford, Conn · UCCL09321
- SLC to Charles E. Perkins, 2 September 1882 · Elmira, N.Y · UCCL02262
- SLC to Charles E. Perkins, 6 September 1882 · Elmira, N.Y · UCCL02265
- SLC to Harriet E. Whitmore, 18 November 1882 · Hartford, Conn · UCCL09324
- SLC to Ellen C. Taft, 12 December 1882 · Hartford, Conn · UCCL02315
- SLC to Charles J. Langdon, 15 January 1883 · Hartford, Conn · UCCL02260
- SLC to Matthew H. Hewins, 10 April 1883 · Hartford, Conn · UCCL02369
- SLC, OLC to Charles J. Langdon, 24 April 1883 · Hartford, Conn · UCCL02375
- SLC to Unidentified, 13 May 1883 · Hartford, Conn · UCCL10438
- SLC to Karl Gerhardt and Hattie J. Gerhardt, 1 August 1883 · Elmira, N.Y · UCCL02818
- SLC to Ellen C. Taft, 14 August 1883 · Elmira, N.Y · UCCL02821
- SLC to Olivia Lewis Langdon, 19 August 1883 · Elmira, N.Y · UCCL02824
- SLC to Jervis Langdon II, 19 December 1883 · Hartford, Conn · UCCL02867
- SLC to James N. Kimball, 4 January 1884 · Hartford, Conn · UCCL02886
- SLC to Karl Gerhardt and Hattie J. Gerhardt, 5 April 1884 · Hartford, Conn · UCCL12036
- SLC to Francis E. Bliss, 11 May 1884 · Hartford, Conn · UCCL02974
- SLC to Cincinnatus A. Taft, 7–14 June 1884 · Hartford, Conn · UCCL02991
- SLC to Charles H. Clark, 24 June 1884 · Elmira, N.Y · UCCL02994
- SLC to Ellen C. Taft, July 1884 · Elmira, N.Y · UCCL03000
- SLC to Ellen C. Taft, 10 July 1884 · Elmira, N.Y · UCCL08928
- SLC to Hartford Courant editor, 18 July 1884 · Elmira, N.Y · UCCL01540
- SLC to Thomas W. Russell, 14–15 October 1884 · Hartford, Conn · UCCL03007
- SLC to OLC, 15 November 1884 · Boston, Mass · UCCL12021
- SLC to OLC, Unknown date · Unknown place · UCCL09329
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