21Peter S. Du Ponceau to Thomas Jefferson, 5 December 1817 (Jefferson Papers)
The two letters which you have done me the honor to write to me, dated the 6 th & 7 th ultimo ,...
22Peter S. Du Ponceau to Thomas Jefferson, 9 October 1820 (Jefferson Papers)
I take the liberty of introducing to you in the person of M r L. C. Vanuxem , the bearer hereof,...