In August 1921, an estimated 15,000 coal miners and their allies took part in the largest armed labor uprising in U.S. history after nearly a decade of struggle over deplorable mine and company-town conditions, antiunion repression, and the violence of the mine guard system in West Virginia. The conflict grew from the 1912 strike on Paint Creek and Cabin Creek, where miners and their families formed tent colonies, endured winter hardship and deadly attacks, won concessions after a year, and organized into locals of the United Mine Workers of America, but Logan, Mingo, and McDowell counties remained nonunion. In May 1920, miners in Mingo County struck, and Matewan police chief Sid Hatfield became a hero by temporarily stopping evictions by mine guards; when guards later tried to arrest him, the fight that followed killed seven mine guards, two miners, and the mayor of Matewan, prompting Governor Ephraim Morgan to declare martial law in Mingo County. The crackdown fell on unionizing miners, with activists jailed without trial and families assaulted in makeshift camps, and after Hatfield and his deputy Ed Chambers were murdered by mine guards on the McDowell County courthouse steps on August 1, 1921, while unarmed and with their wives, many miners concluded they were fighting to reclaim their rights as American citizens. Hundreds gathered at Marmet, formed an encampment on Lens Creek, and, wearing red bandanas as a sign of solidarity, became known as the Redneck Army under Bill Blizzard, a 28-year-old miner from Cabin Creek. They aimed to free jailed miners, help win the Mingo strike, and unionize the southern counties, but first had to pass through Logan County, where Sheriff Don Chafin, paid by coal operators, had assembled 3,000 deputies and mine guards armed with machine guns along Blair Mountain's 15-mile ridgeline. Beginning on August 31, columns of miners led by World War I veterans launched a disciplined assault, using cover and trying to flank the defenders, while for four days automatic weapons and rifle fire echoed around the mountain. The miners were aided by volunteer nurses, supporters who donated supplies and arms, and local volunteers who prepared meals, and the fighting drew national attention until President Warren Harding sent four regiments of the U.S. Army, which arrived on September 3. Unwilling to fight the federal army, Blizzard negotiated a ceasefire the next day, and the Redneck Army withdrew, with some miners surrendering their weapons. Hundreds of miners were indicted for crimes including murder and treason, but at the Treason Trials in Charles Town the following year a jury acquitted Blizzard, leading prosecutors to drop most charges against others, while Chafin and the coal operators were never charged. The conditions that produced the uprising—company towns and stores, low wages, dangerous work, blacklisting, forced evictions, and brutal mine guards—continued for another decade until federal labor law changes gave miners another chance to unionize.