December 9, 1948
The United Nations adopted the Convention on the Prevention and Punishment of the Crime of Genocide. The document is often referred to as the Genocide Convention. The United States did not ratify it until November 4, 1988 — 40 years later. The leader of the ratification campaign in the U.S. Senate was Wisconsin Senator William Proxmire, who spoke on the subject every day the Senate was in session for 20 years.
