On December 30, 1936, workers sat down on assembly lines in Flint, including the Chevrolet and Fisher Body plants across Chevrolet Avenue, in a pivotal event in American labor history. Their strike was intended to improve working conditions and to force General Motors to recognize their new union, the United Auto Workers. Violence erupted between city police and the strikers, and the National Guard was called in to restore order. After 14 days GM agreed to recognize the UAW, and soon the auto industry was completely unionized.