A new constitutional amendment submitted by Congress in December 1917 prohibited "the manufacture, sale, or transportation of intoxicating liquors within, the importation thereof into, or the exportation thereof from the United States and all territory subject to the jurisdiction thereof for beverage purposes". The amendment was ratified and became law on January 16, 1919. On October 28, 1919, Congress passed the National Prohibition Act, also known as the Volstead Act, which provided enabling legislation to implement the 18th Amendment. After a year's required delay, national prohibition began on January 16, 1920.