This is a May 16, 1933 letter to the U.S. Treasury Secretary from the head of the Farm Products Chemical Company of America (and its lawyers/lobbyists) advocating federal legislation to levy an additional surtax on gasoline unless that gasoline includes a minimum percentage of ethanol that would quickly rise to 10 percent of the total.
Congress did not enact tax-related legislation for ethanol use until the Energy Tax Act of 1978, which created a federal tax credit for gasoline blended with ethanol. The cost of this tax credit was originally borne by the Highway Trust Fund, but the burden was switched to the general fund in 2004. The ethanol tax credit was allowed to expire in 2012, but only after Congress had enacted the Renewable Fuels Standard, which mandates that a certain minimum number of gallons of ethanol be blended into U.S. gasoline each year, as part of the Energy Policy Act of 2005.