The first official flag of the Confederate States of America – called the "Stars and Bars" – originally had seven stars, representing the first seven states that initially formed the Confederacy. As more states joined, more stars were added, until the total was 13 (two stars were added for the divided states of Kentucky and Missouri). During the First Battle of Bull Run, (First Manassas) it sometimes proved difficult to distinguish the Stars and Bars from the Union flag. To rectify the situation, a separate "Battle Flag" was designed for use by troops in the field. Also known as the "Southern Cross", many variations sprang from the original square configuration.