On March 9, 1841, the US Supreme Court ruled the kidnapped slaves from the Spanish schooner the Amistad were free. From the article:
"Amistad Case
In 1839, 53 illegally purchased African slaves being transported from Cuba aboard the Spanish-built schooner Amistad staged a successful mutiny. They were later intercepted by an American brig off the coast of Long Island and thrown in jail. While President Martin Van Buren was among those who favored extraditing the Africans to Cuba, they were eventually allowed a trial, and a federal district court judge ruled they were not liable for their actions. Former president John Quincy Adams argued on behalf of the slaves when the appeal was brought before the U.S. Supreme Court, which eventually determined the Africans to be free men.
In 1839, fifty-three illegally purchased African slaves being transported from Cuba on the ship Amistad managed to seize control of the vessel. They killed two crew members and ordered the remainder to head for Africa. But by altering course at night, when the position of the sun did not reveal the ship’s course, they sailed in a northeasterly direction. Eventually, the Amistad was intercepted by an American brig off the coast of Long Island. The two Spaniards who had enslaved the Africans were freed by the Americans, and the slaves were imprisoned. President Martin Van Buren, along with many newspaper editors, favored extraditing the Africans to Cuba. But abolitionists and other northern sympathizers won an American trial for them.
At a hearing in Hartford, a federal district court judge ruled that the Africans were not liable for their actions because they had been enslaved illegally. The case then proceeded on appeal to the Supreme Court, where former president John Quincy Adams, defending the Africans, argued that they should be granted their freedom. The Court agreed, ruling that since the international slave trade was illegal, persons escaping should be recognized as free under American law."