The Homestead Strike was a labor lockout and strike which began on June 30, 1892, culminating in a battle between strikers and private security agents on July 6, 1892. It is one of the most serious labor disputes in U.S. history. The dispute occurred in the Pittsburgh-area town of Homestead, Pennsylvania, between the Amalgamated Association of Iron and Steel Workers (the AA) and the Carnegie Steel Company. The AA was an American labor union formed in 1876. A craft union, it represented skilled iron and steel workers. The AA's membership was concentrated in ironworks west of the Allegheny Mountains. The union negotiated national uniform wage scales on an annual basis; helped regularize working hours, workload levels and work speeds; and helped improve working conditions. It also acted as a hiring hall, helping employers find scarce puddlers and rollers.