Rancho Santa Fe, Calif. - A rare and important Society of Cincinnati diploma signed by George Washington in a strong hand with rich, brown ink comes to auction Aug. 30. Founded in 1783, the society sought to preserve the ideals and fellowship of the Revolutionary War's officers, and to influence the government to honor pledges it had made to officers who fought for American independence. The document offered by Early American of Rancho Santa Fe, Calif., is dated Dec. 11, 1783, and also boasts the signature of Henry Knox, Washington's future Secretary of War.