The Anti-Heroin Act of 1924 is a United States federal law prohibiting the importation and possession of opium for the chemical synthesis of an addictive narcotic known as diamorphine or heroin. The Act of Congress amended the Smoking Opium Exclusion Act of 1909 which authorized the importation of the poppy plant for medicinal purposes utilizing an opium pipe or vaporization to consume the euphoric opiate. The H.R. 7079 legislation was passed by the 68th United States Congressional session and enacted into law by the 30th President of the United States Calvin Coolidge on June 7, 1924.