In September 1851, a Maryland slaveholder named Edward Gorsuch was killed when he attempted to seize four escaped men at the Christiana, Pennsylvania farmhouse of William Parker, a Black underground-railroad leader whose armed self-defense network had resolved to resist renditions by force. The Fillmore administration, determined to make an example, charged thirty-eight men — most of them Black farmers, plus white miller Castner Hanway, who had refused a federal marshal's order to assist — with treason against the United States: the largest mass treason indictment in American history.
The theory that refusing to help catch a fugitive amounted to levying war collapsed at the first trial. Defended by Thaddeus Stevens, Hanway was acquitted in fifteen minutes in December 1851, and the government abandoned the remaining cases. The defendants had spent months in Moyamensing Prison, but the verdict established that Northern juries would not treat resistance to the Fugitive Slave Act as treason — while Parker and the men he protected escaped to Canada, beyond the law's reach.