The 1970 Comprehensive Drug Abuse Prevention and Control Act replaced all previous drug laws, put drugs under federal control, and increased funding for prevention and treatment. It classified drugs into 5 schedules based on their medical use and abuse potential, and assigned penalties for illegal drug manufacture, distribution, and possession. The Act also established rules for prescribing physicians and has been amended several times since.
Image sources: National Library of Medicine (Image Ch03_01CocaWine) Library of Congress Prints and Photographs Division (Image Ch03_02PatMedHoofland) PhotoLink/Getty Images (Image Ch03_11DrugDevelopment)