Rittenhouse, David

Philadelphia, PA — Founded in 1743 by Benjamin Franklin and John Bartram to promote Useful Knowledge. Philosophical Hall (1789) is now a museum featuring art, scientific instruments, rare books, original manuscripts, natural history specimens, and curiosities.

The Farm Book, plus the elaborate chronologies made by Jefferson scholars which document almost every day of his life, demonstrate that contrary to what Martha [Jefferson] Randolph told her sons, Jefferson was not only not distant from Sally Hemings but in the same house nine months before the births of each of her seven children, and that she conceived no children when he was not there.

Fawn M. Brodie
Thomas Jefferson: An Intimate History (1974)