1Thomas Cooper to Thomas Jefferson, 21 August 1818 (Jefferson Papers)
American Philosophical Society; and natural history exploration [index entry]
2Thomas Cooper to Thomas Jefferson, 26 August 1818 (Jefferson Papers)
American Philosophical Society; and natural history exploration [index entry]
3Thomas Jefferson to Thomas Cooper, 12 September 1818 (Jefferson Papers)
American Philosophical Society; and natural history exploration [index entry]