The 1920s were years of retreat and defeat for US labor. Then, in 1933, there were 1,695 work stoppages, twice the number of the year before, involving 1,117,000 workers, nearly four times more than the previous year. In 1934, the figures rose still higher: 1,856 strikes involving 1,470,000 workers. And as the Depression decade continued, workers began to win their strikes. During 1934, three strikes, in San Francisco, Toledo and Minneapolis–all fought out almost simultaneously–turned the tide in favor of workers. Each strike showed in practice that with solidarity workers can win, no matter how well-armed and well-funded the bosses’ side is. Socialists played a key role in all three strikes. How did the mass strikes of 1934 change the landscape of the US labor movement, and pave the way for the rise of the CIO’s industrial unions?