High Quality Content by WIKIPEDIA articles! The legal history of cannabis in the United States relates to the regulation of marijuana use for medical or recreational purposes in the United States. Regulations and restrictions on the sale of Cannabis sativa as a drug began as early as 1860. Increased restrictions and labeling of cannabis as a poison began in many states from 1906 onward, and outright prohibitions began in the 1920s. By the mid-1930s Cannabis was regulated as a drug in every state, including 35 states that adopted the Uniform State Narcotic Drug Act.