On July 1, 1839, fifty-three Africans, recently kidnapped into slavery in Sierra Leone and sold at a Havana slave market, revolted on the schooner Amistad. They killed the captain and other crew and ordered the two Spaniards who had purchased them to sail them back to Africa. Instead, the ship was seized off Long Island by a U.S. Coast Guard cutter on August 24, 1839. The Amistad then landed in New London, Connecticut, where the American captain filed for salvage rights to the Amistad's cargo--including the Africans. The two Spaniards claimed ownership themselves, while Spanish authorities demanded the Africans be extradited to Spain and tried for murder.

Connecticut officials, for their part, jailed the Africans and charged them with murder. The slave trade had been outlawed in the U.S. since 1808, but the institution of slavery itself still thrived in the South when the Amistad case entered the federal courts and caught the nation's attention. The Amistad captives remained in custody as the legal focus turned to the property rights claimed by various parties. Abolitionists raised money for the Amistad captives' defense, arguing that the Africans had always been and remained free, and had acted in self-defense. U.S. President Martin Van Buren, loath to anger U.S. slaveholders as he faced the prospect of campaigning for reelection, issued an order of extradition, per Spain's wishes. To President Van Buren's surprise, however, the New Haven federal court's decision preempted the return of the captives to Cuba. The court ruled that no one owned the Africans because they had been illegally enslaved and transported to the New World. The Van Buren administration appealed the decision, and the case came before the U.S. Supreme Court in January 1841.

Abolitionists enlisted former U.S. President John Quincy Adams to represent the Amistad captives' petition for freedom before the Supreme Court. Adams, then a 73-year-old U.S. Congressman from Massachusetts, had in recent years fought tirelessly against Congress's "gag rule" banning anti-slavery petitions. Here, with characteristic humility, Adams accepts the job of representing the Amistad captives, hoping he will "do justice to their cause." Adams spoke before the Court for seven hours and succeeded in moving the majority to decide in favor of freeing the captives once and for all. The Court ordered the thirty surviving captives (the others had died at sea or in jail) returned to their home in Sierra Leone.