The Knights of Pythias is a fraternal organization and secret society founded in Washington, D.C., on February 19, 1864. The Knights of Pythias is the first fraternal organization to receive a charter under an act of the United States Congress. Plaque in Washington, D.C., designating the location where the Knights of Pythias were founded in 1864 The order was founded by Justus H. Rathbone, who had been inspired by a play by the Irish poet John Banim about the historic Greek legend of Damon and Pythias that illustrates the Pythagorean ideals of loyalty, honor, and friendship that are the center of the order.