1Thomas Jefferson to Charles Willson Peale, 8 May 1816 (Jefferson Papers)
machines; threshing [index entry]
2Thomas Jefferson to Charles Willson Peale, 13 June 1815 (Jefferson Papers)
machines; threshing [index entry]
3Thomas Jefferson to Charles Willson Peale, 21 March 1815 (Jefferson Papers)
machines; threshing [index entry]