Used at the start of the American Civil War in 1861, what was the unofficial flag of the Confederate States called?

The Bonnie Blue Flag was an unofficial flag of the Confederate States of America at the start of the American Civil War in 1861. It consists of a single, five-pointed white star on a blue field. It closely resembles the flag of the short lived Republic of West Florida of 1810. The Bonnie Blue Flag was flying above the Confederate batteries that first opened fire on Fort Sumter in Charleston harbor, in South Carolina to begin the Civil War.

Although the name "Bonnie Blue" dates only from 1861, there is no doubt that the Confederate flag is identical with the flag of the Republic of West Florida, which broke away from Spanish West Florida in September 1810 and was annexed by the United States several months later. In 2006, the state of Louisiana formally linked the name "Bonnie Blue" to the West Florida flag by passing a law designating the Bonnie Blue Flag as the official flag of the Republic of West Florida Historic Region.

In 2007, one of six known Bonnie Blue flags from the Civil War was sold at auction for $47,800. The flag had been carried by the Confederate 3rd Texas Cavalry and later exhibited as part of the 1936 Texas Centennial Exposition.