Throughout the late 1930s and through the 1940s, workers continued to form unions in record numbers and income inequality steadily fell. In just four years, from 1934 to 1938, the percentage of nonagricultural workers in unions jumped from 11.5 percent to 26.6 percent. This would have been unimaginable in 1932. The gap between the billionaires and workers declined because the power equation shifted. The workers made that shift by making strong organizations of their own, bargaining collectively, and holding the kind of strikes that could create a crisis when employers were unreasonable. Big gains for the whole of the working class were being extracted in key profit sectors of the economy. The mobilization for World War II and the tight labor markets it produced, however, overshadowed serious dangers on the horizon for workers and their new unions.