The postage stamps and postal system of the Confederate States of America carried the mail of the Confederacy for a brief period in U.S. history. Early in 1861 when South Carolina no longer considered itself part of the Union and demanded that the U.S. Army abandon Fort Sumter, plans for a Confederate postal system were already underway. Indeed, the Confederate Post Office was established on February 21, 1861; and it was not until April 12 that the American Civil War officially began, when the Confederate Army fired upon U.S. soldiers who had refused to abandon the fort. However, the United States Post Office Department continued to handle the mail of the seceded states as usual during the first weeks of the war. It was not until June 1 that the Confederate Post Office took over collection and delivery, now faced with the task of providing postage stamps and mail services for its citizens.

The United States Post Office Department was the predecessor of the United States Postal Service, established in 1792. From 1872 to 1971, it was officially in the form of a Cabinet department. It was headed by the postmaster general.