The Constitution of the Confederate States of America was the supreme law of the Confederate States, as adopted on March 11, 1861 and in effect through the conclusion of the American Civil War. The Confederacy also operated under a Provisional Constitution from February 8, 1861 to March 11, 1861. In regard to most articles of the Constitution, the document is a word-for-word duplicate of the United States Constitution. However, there are crucial differences between the two documents, in tone and legal content.