the first clause, section one, says the law was to go into effect one year from its ratification. it was passed by congress on december 18, 1917. the thirty-sixth state (required number for passage) to ratify the amendment did so 394 days later on january 16, 1919. the forty-seventh state to ratify the amendment was new jersey on march 9, 1922. rhode island was the only state to reject ratification of the 18th amendment.