1Enclosure: Ferdinand R. Hassler to Robert Patterson, 2 December 1816 (Jefferson Papers)
Hassler, Ferdinand Rudolph; and watchmaker for Charlottesville [index entry]
2Robert Patterson to Thomas Jefferson, 13 December 1816 (Jefferson Papers)
Hassler, Ferdinand Rudolph; and watchmaker for Charlottesville [index entry]
3Thomas Jefferson to Robert Patterson, 1 January 1817 (Jefferson Papers)
Hassler, Ferdinand Rudolph; and watchmaker for Charlottesville [index entry]
4Thomas Jefferson to Ferdinand R. Hassler, 25 December 1819 (Jefferson Papers)
Hassler, Ferdinand Rudolph; and watchmaker for Charlottesville [index entry]