LaGuardia Committee report

The LaGuardia Committee report was an official scientific report published in 1944 that questioned the prohibition of cannabis in the United States. The report contradicted claims by the U.S. Treasury Department that smoking marijuana deteriorates physical and mental health, assists in criminal behavior and juvenile delinquency, is physically addictive, and is a "gateway" drug to more dangerous drugs.

Source: Wikipedia — LaGuardia Committee report (CC BY-SA 4.0)