In the United States, psilocybin (and psilocin) were first subjected to federal regulation by the Drug Abuse Control Amendments of 1965, a product of a bill sponsored by Senator Thomas J. Dodd. The law—passed in July 1965 and effected on February 1, 1966—was an amendment to the federal Food, Drug and Cosmetic Act and was intended to regulate the unlicensed "possession, manufacture, or sale of depressant, stimulant and hallucinogenic drugs". The statutes themselves, however, did not list the "hallucinogenic drugs" that were being regulated. Instead, the term "hallucinogenic drugs" was meant to refer to those substances believed to have a "hallucinogenic effect on the central nervous system".