In the midst of the national debate over America's energy needs, the issue of "power alcohol" or alcohol used in the internal combustion engine either by itself or in a blend with gasoline, has again raised its head. This chapter focuses on the ethanol side of the question. Many of the leading advocates of power alcohol come from the midwestern farm belt and are urging government support of programs to produce ethanol from fermented grain or agricultural waste. The chapter examines the power alcohol movement during the Great Depression of the 1930s, the most organized previous effort to introduce alcohol as a motor fuel. It analyzes why the movement failed, and describes the opposition of the petroleum industry and related segments of the motor users' lobby. The alcohol and petroleum industries locked horns over their competing processes for the production of butadiene, but with the end of the agricultural depression, the main argument for subsidizing power alcohol had gone.