Franking signature, “J. Adams,” on a 4.75 x 3.25 mailing panel addressed in another hand to “Madam Mercy Warren, Plymouth” and bearing a handwritten “Quincy, MA, Nov. 24” postmark. Writer and playwright Mercy Otis Warren (1728–1814) was known as the "Conscience of the American Revolution.” Her husband, James, first elected to the Massachusetts House of Representatives in 1765, eventually became speaker of the House and President of the Massachusetts Provincial Congress. He later served as paymaster to Washington’s army during the Revolutionary War. In fine condition, with professional repair to area of paper loss along top edge of panel, scattered trivial toning, and a light central vertical fold, not affecting the bold signature. Auction LOA John Reznikoff/PSA/DNA and R&R COA.