Table of Contents
When was marijuana made illegal
1. Early Regulation and Social Context (Pre-1930s):
- In the late 19th and early 20th centuries, cannabis was legal and commonly used in medicines.
- Anti-drug sentiment grew in the early 1900s, partly influenced by xenophobia and anti-Mexican rhetoric following increased immigration after the Mexican Revolution.
- By 1931, 29 U.S. states had already outlawed marijuana independently.
2. Federal Prohibition – Marijuana Tax Act of 1937:
- Passed on August 2, 1937, this law did not criminalize marijuana outright but imposed strict taxes and regulations, effectively banning its use.
- Championed by Harry Anslinger, head of the Federal Bureau of Narcotics, the campaign used racially charged propaganda linking marijuana to violence and moral decay.
- The American Medical Association opposed the Act, citing lack of scientific evidence.
3. International Developments:
- In 1925, cannabis was added to the International Opium Convention, restricting international trade except for medical and scientific purposes.
- This influenced national policies globally, including the United States.
4. Controlled Substances Act of 1970:
- Marijuana was classified as a Schedule I drug, alongside heroin and LSD, under President Richard Nixon’s Controlled Substances Act.
- Schedule I status means:
- High potential for abuse
- No accepted medical use
- Lack of safety under medical supervision
- This classification laid the groundwork for the War on Drugs and strict criminal penalties.
5. Modern Developments (1996–Present):
- California legalized medical marijuana in 1996 (Proposition 215), initiating state-level reform.
- As of 2025, many U.S. states have legalized marijuana for medical and/or recreational use.
- However, federal prohibition remains in effect, although reclassification and legalization efforts are advancing in Congress.
This timeline highlights the progression of marijuana prohibition from early local laws to international conventions and modern federal policy.
