from coal, while other synthetic fuels included 550 million liters of benzene and over one billion liters of synthetic gasoline. All told, 54% of the pre-war German fuel production was derived from non-petroleum sources, of which 8% was ethanol from renewable sources In the 1930s, the Dust bowl drought and Great Depression forced many more farmers to move to the cities looking for work, leaving their alcohol fuel stills behind. Henry Ford, a farmer himself, supported ethanol's use over gas. In 1933, faced with the 25% unemployment of the Great Depression, the European concept of finding new markets for surplus farm products is widely discussed, with ethanol-gasoline blending among the most significant. Fuel blending experiments begin in Peoria, IL, Spokane WA, Lincoln, NE, and Ames, IA. Federal and state governments consider tax advantages to help ethanol production and increase employment among farmers. By 1935 the Chemurgy movement emerges, supported by farmers, Republicans, and Henry Ford. Along with ethanol, chemurgy research included the industrial development of agricultural raw materials such as hemp, soybeans and new products from biological materials, such as hemp & soybean plastics and inks. In 1933, a campaign to end Prohibition in the United States emerges. Concerned about renewed interest in ethanol for fuel, the American Petroleum Institute begins a campaign against ethanol blends, claiming such "will harm the petroleum industry and the automobile industry as well as state and national treasuries by reducing [oil] consumption," the sole beneficiaries allegedly being distillers, railroads (which would transport the alcohol) and bootleggers "to whom would be opened brand new fields of fraud." Prohibition ends with the passage of the Twenty-first Amendment to the United States Constitution on December 5, 1933. From 1933 to 1939, various oil companies and the American Petroleum Institute argued that tax incentives for ethanol would hurt the oil industry, reduce state treasuries, and create a bootlegger' atmosphere around fueling stations. They also claimed alcohol fuel was inferior to gasoline. In 1937, the farm chemurgy movement finds backers for the Agrol ethanol fuel plant, created at Atchison, Kansas. For two years, ethanol blends were sold at around 2,000 service stations in the U.S. Midwest. Agrol plant managers complained of sabotage and bitter infighting by the oil industry, and the cheaper price of gasoline. Agrol sold for 17 cents per gallon, while leaded gasoline sold for 16 cents. In 1939, Agrol production shuts down. In 1942, chemists who