What was the name of the diplomatic incident where the Confederacy sent diplomats to Britain and France and were captured by a Union ship?

The Trent Affair refers to the diplomatic incident during the American Civil War where the Confederate government sent two diplomats, James Mason and John Slidell, to Europe—specifically to Britain and France—in an attempt to gain support for the Confederate cause. These diplomats were captured by the Union navy aboard the British ship HMS Trent. The incident created significant tension between the United States and Britain, as it was perceived as a violation of British sovereignty. The Union ultimately released Mason and Slidell to avoid further diplomatic conflict, but the affair showcased the delicate nature of international diplomacy during the war and the Confederacy's reliance on foreign assistance.

In contrast, Cotton Diplomacy is a term describing the South's strategy to leverage its cotton production as a means to encourage British and French support. The War of 1812 was an earlier conflict involving the United States and Britain. Lastly, Marbury v. Madison was a landmark Supreme Court case that dealt with issues of judicial review, unrelated to the events of the Civil War or international diplomacy in this context.