Member groups Marijuana possession and usage remain illegal under federal law. In 1996, California became the first state to legalize marijuana for medical use. Since then, 37 states and the District of Columbia have legalized medical marijuana, in addition to the U.S. territories of Guam, the U.S. Virgin Islands, Puerto Rico, and the Northern Mariana Islands. The United States's relationship with marijuana dates back to the Colonial Era. American production of hemp (the cannabis plant) was encouraged by the government in the 17thCentury for the production of rope, sails, and clothing.Domestic productionof hemp flourished until after the Civil War, when imports replaced hemp. In the late 19th Century, marijuana ta reda på detta här became a popular ingredient in many medicinal products and was sold openly in pharmacies.