Volstead, Andrew Joseph, 1860-1947, American legislator, b. Goodhue co., Minn. A lawyer, he held several local offices in Minnesota before serving (1903-23) in the U.S. House of Representatives. He sponsored many measures in Congress and became a national figure as the author of the Volstead Act. Officially the National Prohibition Act of 1919, the federal law (passed over the veto of President Wilson) made provisions for the enforcement of the Eighteenth Amendment. The act defined an intoxicating beverage as one containing more than .5% alcohol by volume. It also gave federal agents the power to investigate and prosecute violations of the amendment. The act was modified (1933) in order to permit the sale of 3.2% beer and wine, and became void after the repeal of the Eighteenth Amendment late in 1933. See also prohibition.