In 1841, at the request of Lewis Tappan and Ellis Gray Loring, Adams joined the case of "United States v. The Amistad". Adams went before the Supreme Court on behalf of African slaves who had revolted and seized the Spanish ship "Amistad". Adams appeared on February 24, 1841, and spoke for four hours. His argument succeeded; the Court ruled in favor of the Africans, who were declared free and returned to their homes.