Addressees: Johnson, Robert Underwood
- SLC to Robert U. Johnson, 18 March 1885 · Hartford, Conn · UCCL03191 CtHMTH
- SLC to Robert U. Johnson, 6 July 1885 · Elmira, N.Y · UCCL03252 C4
- SLC to Robert U. Johnson, 28 July 1885 · Elmira, N.Y · UCCL03268 CU-MARK
- SLC to Robert Underwood Johnson, 15 and 17 August 1885 · Elmira, N.Y · UCCL02424 CtHMTH
- SLC to Robert U. Johnson, 8 September 1885 · Elmira, N.Y · UCCL03285 CU-MARK
- SLC to Robert U. Johnson, 31 October 1887 · Hartford, Conn · UCCL03663 ViU
- SLC to Richard Watson Gilder or Robert U. Johnson or Clarence C. Buel, 12 August 1888 · Elmira, N.Y · UCCL02684 NN-BGC
- SLC to Robert U. Johnson, 6 September 1888 · Elmira, N.Y · UCCL03757 NN
- SLC to Robert U. Johnson, 30 July 1889 · Elmira, N.Y · UCCL12351
- SLC to Robert U. Johnson, 3 August 1889 · Elmira, N.Y · UCCL03921 ViU
- SLC to Robert U. Johnson, 16 August 1889 · Elmira, N.Y · UCCL10828 InU-Li
- SLC to Robert U. Johnson, 24 August 1889 · Elmira, N.Y · UCCL11365 CU-MARK
- SLC to Robert Underwood Johnson, 27 October 1889 · Hartford, Conn · UCCL13651
- SLC to Robert U. Johnson, 10 July 1891 · Aix-les-Bains, France · UCCL04220 CtHMTH
- SLC to Robert U. Johnson, 30 May 1894 · Paris, France · UCCL09551 NNUnC
- SLC to Robert U. Johnson, 30 May 1895 · Elmira, N.Y · UCCL04882 ViU
- SLC to Robert U. Johnson, 5and 6 July 1895 · Elmira, N.Y · UCCL04926 NSyU
- SLC to Richard Watson Gilder, Robert U. Johnson, Clarence C. Buel, William Carey, William F. Clark and Mary Mapes Dodge, 17 August 1895 · Vancouver, Canada · UCCL02462 CtHMTH
- SLC to Robert U. Johnson, 11 November 1900 · New York, N.Y · UCCL05901 CLU-SC
- SLC to Robert Underwood Johnson, 31 March 1901 · New York, N.Y · UCCL06030 ViU
- SLC to Robert U. Johnson, 11 October 1901 · Riverdale, N.Y · UCCL08220 NN-BGC
- SLC to Robert U. Johnson, 14 April 1902 · Riverdale, N.Y · UCCL06323 ViU
- SLC to Robert Underwood Johnson, 20 October 1903 · New York, N.Y · UCCL13989
- SLC to Robert U. Johnson, 21 October 1903 · New York, N.Y · UCCL06749 ViU
- SLC to Robert U. Johnson, 10 December 1904 · New York, N.Y · UCCL06958 NNAL
- Isabel V. Lyon for SLC to Robert U. Johnson, 7 April 1905 · New York, N.Y · UCCL07027 NNAL
- SLC to Robert U. Johnson, 28 April 1905 · New York, N.Y · UCCL07034 NNAL
- SLC to Robert U. Johnson, 3 May 1905 · New York, N.Y · UCCL07039 NNAL
- Isabel V. Lyon for SLC to Robert U. Johnson, 29 September 1905 · Dublin, N.H · UCCL07153 NNAL
- SLC per Isabel V. Lyon to Robert U. Johnson, 19 December 1905 · New York, N.Y · UCCL07266 NNAL
- SLC to Robert U. Johnson, 2 December 1906 · New York, N.Y · UCCL07581 ViU
- SLC per Isabel V. Lyon to Robert U. Johnson, 31 May 1907 · Tuxedo Park, N.Y · UCCL07737 NNAL
- Isabel V. Lyon for SLC to Robert U. Johnson, 1 January 1908 · New York, N.Y · UCCL12340 NNAL
- SLC to Robert U. Johnson, 5 June 1909 · Redding, Conn · UCCL08416 ViU
- SLC to Robert U. Johnson, Unknown date · Unknown place · UCCL08994 CU-MARK
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