In the autumn of 1861 the Confederacy was counting on King Cotton to pull Britain and France into the war, while William H. Seward worked to keep Europe out. Jefferson Davis sent envoys James Mason and John Slidell, who slipped out of Charleston to Cuba and boarded the British mail ship RMS Trent in Havana. On November 8, 1861, Captain Charles Wilkes of the USS San Jacinto fired across the Trent’s bow in the Bahama Channel, sent a boarding party, declared the two men contraband of war and took them, letting the ship sail on rather than sending it to a prize court.

Wilkes was hailed in the North, but Lincoln called the prisoners white elephants as the stock market fell and New York banks suspended gold payments. In London, Lord Palmerston’s government halted saltpeter exports, planned a blockade and sent over 11,000 troops to Canada, and drafted an ultimatum with a seven-day deadline. Prince Albert, dying of typhoid, softened it to suggest Wilkes had acted without instructions. At a Christmas Day cabinet meeting, Seward built a reply on Wilkes’s procedural error and America’s own stance from the War of 1812, and the envoys were released in January 1862.

• Britain’s declared neutrality gave the Confederacy belligerent status, allowing its ships to use neutral ports.
• Seizing people from a neutral ship was the practice the United States had opposed in the lead-up to the War of 1812.
• Congress proposed striking a gold medal for Wilkes after he returned with the envoys.
• France backed Britain’s position, leaving the United States isolated as the deadline approached.
• The crisis contributed to the U.S. government issuing greenbacks to keep the wartime economy running.