The Samuel F. B. Morse Papers at the Library of Congress
Letterbooks
Letterbook---2 June 1854-8 October 1855
Letterbook---8 October 1855-23 October 1857
Letterbook---22 December 1858-6 July 1860
Letterbook---24 May 1860-18 February 1862
Letterbook---14 June 1861-26 November 1863
Letterbook---21 February 1862-30 November 1863
Letterbook---26 November 1863-22 July 1865
Letterbook---7 June 1865-19 June 1866
Letterbook---29 September 1866-17 February 1868
Letterbook---24 February-21 November 1868
Letterbook---1 December 1868-23 June 1870
Letterbook---30 June 1870-11 October 1871
Letterbook---24 June 1871-14 March 1872
