Addressees: Lyon, Isabel V
- SLC to IVL, 17-18 February 1904 · Florence, Italy · UCCL04218 PP
- SLC to Isabel V. Lyon, 17 August 1904 · New York, N.Y · UCCL06912 ViU
- SLC per Ralph W. Ashcroft to Isabel V. Lyon, 7 October 1904 · New York, N.Y · UCCL10888 NPV
- SLC to Isabel V. Lyon, 12 October 1904 · New York, N.Y · UCCL06926 CU-MARK
- SLC to Isabel V. Lyon, 18 October 1904 · New York, N.Y · UCCL09495 CU-MARK
- SLC to Isabel V. Lyon and Jean Clemens, 18 October 1904 · New York, N.Y · UCCL06931 NRU
- SLC to Isabel V. Lyon, 12 May 1905 · New York, N.Y · UCCL10760 CU-MARK
- SLC to Isabel V. Lyon, 15 August 1905 · Norfolk, Conn · UCCL08242 NN-BGC, CU-MARK
- SLC to Isabel V. Lyon, 20–21 August 1905 · Norfolk, Conn · UCCL07112 CU-MARK
- SLC to Isabel V. Lyon, 31 August 1905 · Dublin, N.H · UCCL07111 CU-MARK
- SLC to IVL, September 1905 · Dublin, N.H · UCCL13531 NNPM
- SLC to IVL, September 1905 · Dublin, N.H · UCCL13530 NNPM
- SLC to Isabel V. Lyon, 6 October 1905 · Dublin, N.H · UCCL07162 CU-MARK
- SLC to Isabel V. Lyon, 25 October 1905 · Boston, Mass · UCCL07187 ViU
- SLC to Isabel V. Lyon, 14 March 1906 · New York, N.Y · UCCL10822 InU-Li
- SLC to Isabel V. Lyon, 14 June 1906 · Dublin, N.H · UCCL11110 NSyU
- SLC to Isabel V. Lyon, 10 July 1906 · New York, N.Y · UCCL07478 CU-MARK
- SLC to Isabel V. Lyon, 12 July 1906 · New York, N.Y · UCCL06973 CU-MARK
- SLC to Isabel V. Lyon, 16 July 1906 · New York, N.Y · UCCL10889 NPV
- SLC to Isabel V. Lyon, 25 July 1906 · Dublin, N.H · UCCL12887 CU-MARK
- SLC to Isabel V. Lyon, 15 August 1906 · Dublin. N.H · UCCL07115 CU-MARK
- SLC to Isabel V. Lyon, 20 September 1906 · New York, N.Y · UCCL07527 InU-Li, CU-MARK
- SLC to Isabel V. Lyon, 25 September 1906 · New York, N.Y · UCCL07476 NN5
- SLC to Isabel V. Lyon, 27 September 1906 · New York, N.Y · UCCL12164 CU-MARK
- SLC to Isabel V. Lyon, 7 February 1907 · New York, N.Y · UCCL09273 NN-BGC
- SLC to Isabel V. Lyon or Albert B. Paine, after 17 April 1907 · UCCL13759 CU-MARK
- SLC to Isabel V. Lyon, 29 April 1907 · Fort Monroe, Va · UCCL07698 CU-MARK
- Samuel L. Clemens to Isabel V. Lyon, 22 May 1907, Tuxedo Park, NY · UCCL13614 NPV
- SLC to Isabel V. Lyon, 30 September 1907 · Tuxedo Park, N.Y · UCCL10819 InU-Li
- SLC to Isabel V. Lyon, Unknown date · Unknown place · UCCL09980
- SLC to Isabel V. Lyon, 29 May 1909 · Redding, Conn · UCCL08407 CU-MARK
- SLC to Isabel V. Lyon, Unknown date · Unknown place · UCCL11317 ODa2
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