William L Patterson was an African-American leader in the Communist Party USA and head of the International Labor Defense, which defended Sacco and Venzetti and a member of the Civil Rights Congress. He is best known for presenting a petition to the UN along with Paul Robeson in 1951 accusing the US government of genocide against Black Americans. The petition was book length and documented at least 10,000 lynchings in the US since the abolition of slavery. Its conclusion states "the oppressed Negro citizens of the United States, segregated, discriminated against, and long the target of violence, suffer from genocide as the result of the consistent, conscious, unified policies of every branch of government." The petition was supposed to be delivered by WEB Dubois who the US denied a visa and Patterson's passport was revoked on his return from this trip. Patterson and Robeson were harassed and persecuted by the FBI and other federal agencies for the rest of their lives. The petition received almost no coverage in the United States but was read widely around the world and shaped opinions of the US government's racist policies for years to come.