Schedule I of the DEA's Drug Schedules states that every drug therein has "no currently accepted medical use in treatment in the United States."
Marijuana has many widely accepted medical uses, and the effort to re-schedule Marijuana is widely endorsed by the American Medial Association and many other medical institutions. (http://www.ama-assn.org/resources/doc/csaph/csaph-report3-i09.pdf)
Efforts by scientists and doctors to re-schedule Marijuana have been thwarted for decades by politicians. The most studied plant in the world is purported to have "insufficient research behind its medical uses", and advanced research and regulation of Marijuana in the U.S. is impossible due to the policy restrictions placed on all Schedule I substances.
End the injustice, reform our corrupt laws.