Use of heroin peaked between 1969 and 1971, marijuana between 1978 and 1979, and cocaine between 1987 and 1989. A major decline in the use of opium started after the Harrison Act of 1914 was initiated.
An overarching effort to impose mandatory penalties for federal drug crimes took place in the 1980s. This caused many drug crimes that were common at the time to carry mandatory minimum sentences of 5 to 10 years in a federal prison.
In 1996, California voters passed Proposition 215, legalizing the growing and use of marijuana for medical purposes. This created significant legal and enforcement conflict between federal and state government laws. Courts have since decided that a state law in conflict with a federal law concerning cannabis is not valid. Cannabis is restricted by federal law (see Gonzales v. Raich). In 2010 California Proposition 19 (also known as the Regulate, Control & Tax Cannabis Act) was defeated with 53.5% 'No' votes, and 46.5% 'Yes' votes.
Pursuant to regulations (34 C.F.R. 86) required by the Drug-Free Schools and Communities Act Amendments of 1989 (codified at 20 U.S.C. § 1011i), as a condition of receiving funds or any other form of financial assistance under any Federal program, an institution of higher education must certify that it has adopted and implemented a drug prevention program which adheres to regulations in 34 C.F.R. 86.100. It has recently gained renewed attention due to Colorado Amendment 64.