1Thomas Jefferson to David Gelston, 2 July 1812 (Jefferson Papers)
Vaughan, John; as Philadelphia contact [index entry]
2José Corrêa da Serra to Thomas Jefferson, 6 September 1813 (Jefferson Papers)
Vaughan, John; as Philadelphia contact [index entry]
3John Vaughan to Thomas Jefferson, 14 May 1818 (Jefferson Papers)
Vaughan, John; as Philadelphia contact [index entry]
4Thomas Jefferson to John Vaughan, 28 May 1818 (Jefferson Papers)
Vaughan, John; as Philadelphia contact [index entry]