The Battle of Blair Mountain was one of the largest civil uprisings in United States history and the largest armed rebellion since the American Civil War. For five days in late August and early September 1921, in Logan County, West Virginia, some 10,000 armed coal miners confronted 3,000 lawmen and strikebreakers, called the Logan Defenders, who were backed by coal mine operators during an attempt by the miners to unionize the southwestern West Virginia coalfields. The battle ended after approximately one million rounds were fired, and the United States Army intervened by presidential order.