11Horatio G. Spafford to Thomas Jefferson, 2 August 1813 (Jefferson Papers)
A Gazetteer of the State of New-York (H. G. Spafford) [index entry]
12Horatio G. Spafford to Thomas Jefferson, 22 March 1814 (Jefferson Papers)
A Gazetteer of the State of New-York (H. G. Spafford) [index entry]
13Horatio G. Spafford to Thomas Jefferson, 30 March 1814, with Postscript 7 April 1814 (Jefferson Papers)
A Gazetteer of the State of New-York (H. G. Spafford) [index entry]
14Horatio G. Spafford to Thomas Jefferson, 17 December 1813 (Jefferson Papers)
A Gazetteer of the State of New-York (H. G. Spafford) [index entry]