1Thomas Jefferson to Thomas Sumter, 23 July 1821 (Jefferson Papers)
Sumter, Thomas (1768–1840); and minerals for TJ [index entry]
2Daniel Brent to Thomas Jefferson, 5 September 1821 (Jefferson Papers)
Sumter, Thomas (1768–1840); and minerals for TJ [index entry]
3Thomas Jefferson to John Barnes, 10 September 1821 (Jefferson Papers)
Sumter, Thomas (1768–1840); and minerals for TJ [index entry]
4John Barnes to Thomas Jefferson, 18 September 1821 (Jefferson Papers)
Sumter, Thomas (1768–1840); and minerals for TJ [index entry]