Marijuana is labeled a Schedule I drug by the federal government under the Controlled Substances Act of 1970. Its production, distribution, possession and use are thus criminally prohibited. The drug’s negative treatment from the federal government stems from the Prohibition Era, culminating in the War on Drugs. However, evolving public sentiment against marijuana criminalization and its medical use has led to the drug being fully or partially legalized by state statutes in 21 states and the District of Columbia. Notwithstanding federal statutes, state laws pose a significant challenge to federalism and its treatment of marijuana.