Nearly six thousand conscientious objectors went to federal prison during the Second World War — one in six federal prisoners by war's end — most of them Jehovah's Witnesses, alongside the radical pacifists whose draft-card refusals put them in Danbury, Lewisburg, and Ashland. Inside, they turned the prisons into laboratories of nonviolence: the Danbury strike of 1943 desegregated the dining hall after 135 days, and hunger strikes by Stanley Murphy and Louis Taylor at Lewisburg lasted into forced-feeding for over a year.

The war's CO prisoners — Bayard Rustin, David Dellinger, Ralph DiGia, Bill Sutherland among them — carried prison-tested tactics directly into the postwar movements: Rustin from a Kentucky cellblock to the March on Washington, Dellinger to the Chicago conspiracy dock. Their strikes were the first sustained direct-action assault on prison segregation anywhere in America.