11Horatio G. Spafford to Thomas Jefferson, 27 August 1813 (Jefferson Papers)
A Gazetteer of the State of New-York (H. G. Spafford) [index entry]
12Thomas Jefferson to Horatio G. Spafford, 15 August 1813 (Jefferson Papers)
A Gazetteer of the State of New-York (H. G. Spafford) [index entry]
13Horatio G. Spafford to Thomas Jefferson, 2 August 1813 (Jefferson Papers)
A Gazetteer of the State of New-York (H. G. Spafford) [index entry]
14Horatio G. Spafford to Thomas Jefferson, 14 January 1810 (Jefferson Papers)
A Gazetteer of the State of New-York (H. G. Spafford) [index entry]