1Thomas Jefferson to Isaac McPherson, 13 August 1813 (Jefferson Papers)
machines; drill [index entry]
2Isaac McPherson to Thomas Jefferson, 28 August 1813 (Jefferson Papers)
machines; drill [index entry]
3Thomas Jefferson to Isaac McPherson, 18 September 1813 (Jefferson Papers)
machines; drill [index entry]
4Samuel P. Parsons to Thomas Jefferson, 16 March 1814 (Jefferson Papers)
machines; drill [index entry]
5Thomas Jefferson to Samuel P. Parsons, 19 April 1814 (Jefferson Papers)
machines; drill [index entry]
6Charles Willson Peale to Thomas Jefferson, 23 December 1815 (Jefferson Papers)
machines; drill [index entry]
7Thomas Jefferson to Charles Willson Peale, 8 May 1816 (Jefferson Papers)
machines; drill [index entry]