1Horatio G. Spafford to Thomas Jefferson, 14 January 1810 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
2Horatio G. Spafford to Thomas Jefferson, 2 August 1813 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
3Thomas Jefferson to Horatio G. Spafford, 15 August 1813 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
4Horatio G. Spafford to Thomas Jefferson, 27 August 1813 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
5Horatio G. Spafford to Thomas Jefferson, 17 December 1813 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
6Horatio G. Spafford to Thomas Jefferson, 28 January 1814 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
7Thomas Jefferson to Horatio G. Spafford, 17 March 1814 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
8Horatio G. Spafford to Thomas Jefferson, 22 March 1814 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
9Horatio G. Spafford to Thomas Jefferson, 30 March 1814, with Postscript 7 April 1814 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
10Horatio G. Spafford to Thomas Jefferson, 23 January 1815 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
11Horatio G. Spafford to Thomas Jefferson, 6 April 1815 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
12Horatio G. Spafford to Thomas Jefferson, 23 November 1816 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
13Horatio G. Spafford to Thomas Jefferson, 5 October 1819 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]
14Horatio G. Spafford to Thomas Jefferson, 28 February 1822 (Jefferson Papers)
Spafford, Horatio Gates; A Gazetteer of the State of New-York [index entry]