Answer: Oregon prohibited liquor 1916. Three years after Oregon went dry the 18th Amendment to the U.S. Constitution was ratified. It prohibited the “manufacture, sale, or transportation of intoxicating liquors…”. Prohibition ended on December 5, 1933, with the ratification of the 21st Amendment. One of the last places that continued our state’s temperance tradition was Monmouth, Oregon, which stayed dry until 2002.