In May 1937, seventy thousand workers walked off their jobs at four large steel companies known collectively as “Little Steel.” The strikers sought to make the companies retreat from decades of antiunion repression, abide by the newly enacted federal labor law, and recognize their union. For two months a grinding struggle unfolded, punctuated by bloody clashes in which police, company agents, and National Guardsmen ruthlessly beat and shot unionists. At least sixteen died and...