1John Adams to Thomas Jefferson, 18 July 1813 (Jefferson Papers)
Outlines of An Historical View of the Progress of the Human Mind (Condorcet) [index entry]
2John Adams to Thomas Jefferson, with postscript by Abigail Adams, 20 June 1815 (Jefferson Papers)
Outlines of An Historical View of the Progress of the Human Mind (Condorcet) [index entry]