1Timothy Dwight Porter to Thomas Jefferson, [ca. 10 March 1820] (Jefferson Papers)
I send for your inspection a copy of the constitution of the Am. Geol. Soc. among whose members...
2Thomas Jefferson to Timothy Dwight Porter, 26 March 1820 (Jefferson Papers)
Th: Jefferson returns his thanks to mr Porter for the copy of the constn of the Amer. geolog....