The Trent Affair is the name given to a diplomatic incident that occurred November 8, 1861 during the American Civil War. In an attempt to gain support for the Confederate States of America from European nations during the war, the CSA dispatched two diplomats, James M. Mason and John Slidell to Europe via RMS Trent, a British mail steamer. They left from Havana, Cuba, but were captured when passing through the Union naval blockade, by Captain Charles Wilkes of USS San Jacinto. Both men were held at Fort Warren in Boston harbor.
The arrest nearly brought the United States to war with Britain. Britain demanded the release of the two diplomats and sent troops to Canada to prepare for war. Being a British colony, Canada was directly threatened by the affair. Its militia grew substantially as Canadian provinces were called on by Minister of Militia and Defence, John A. Macdonald (future Father of Confederation), to increase their active militia to 50,000 men from 10,000. Nova Scotia alone trained and armed 45,000 men. Britain and the Southern states had close economic ties because of their mutual involvement in the cotton trade (see cotton diplomacy). Finally United States Secretary of State William H. Seward apologized to the British for the incident. Mason and Slidell were released in January of 1862.