The Trent Affair was a diplomatic crisis that took place between the United States and Great Britain from November to December 1861, during the U.S. Civil War (1861-65). The crisis erupted after the captain of the USS San Jacinto ordered the arrest of two Confederate envoys sailing to Europe aboard a British mail ship, the Trent, in order to seek support for the South in the Civil War. The British, who had not taken sides in the war, were outraged and claimed the seizure of a neutral ship by the U.S. Navy was a violation of international law. In the end, President Abraham Lincoln’s administration released the envoys and averted an armed conflict with Britain.

The Trent Affair: Confederate Envoys Arrested

On November 8, 1861, Confederate diplomatic envoys James Mason (1798-1871) of Virginia and John Slidell (1793-1871) of Louisiana were aboard the Trent, a British mail steamer, sailing through the Bahama Channel (between the Bahamas and Cuba), when the vessel was intercepted by the USS San Jacinto, captained by Charles Wilkes (1798-1877). Mason and Slidell and their secretaries, who were headed to England and France to lobby for recognition of the Confederacy, were arrested, transported to Boston and imprisoned at Fort Warren. The Trent was allowed to continue its journey after the men’s arrest.

Did you know? Years before he was involved in the Trent Affair, Captain Charles Wilkes commanded the U.S. Exploring Expedition of the Pacific Ocean and surrounding areas, from 1838 to 1842. The expedition is credited with discovering that Antarctica is a separate continent.

In America, Northerners hailed Captain Wilkes for actions. However, the British were outraged when word of the interception reached London in late November. They had not taken sides in the Civil War and their policy was to accept any paying customer who wished to travel aboard their ships. The British government dispatched a message to the American government demanding the release of Mason and Slidell, along with an apology for the transgression of British rights on the high seas.

The Trent Affair: Britain Prepares for War

The British began preparing for war, banning exports of war materials to America and sending troops to Canada. Plans were made to attack the American fleet that was blockading the South. The British also planned a blockade of Northern ports. At the same time, France announced it would back Britain in a conflict with America.

The Trent Affair: Crisis Resolved

In December, Lord Lyons, the British minister to the United States, met with Secretary of State William Seward (1801-72) concerning the fate of Mason and Slidell. Lyons took a hard line during the meeting, and afterward wrote to Lord Russell, the British foreign minister: “I am so concerned that unless we give our friends here a good lesson this time, we shall have the same trouble with them again very soon. Surrender or war will have a very good effect on them.”

Abraham Lincoln (1809-65) and his administration got the message—“One war at a time,” the president said—and decided not to push the issue. On December 27, Seward sent a message to Britain officials in which he disavowed the actions of Captain Wilkes and announced that the envoys would be released. Armed conflict with Great Britain thus was averted.

After Mason and Slidell were set free in early January 1862, they traveled to Europe. However, their mission ultimately was a failure, as they were unable to convince European leaders to support the Confederates in the Civil War.