At the broadest level, a “law” can be defined as a written policy designed to control human behavior. Drug laws, then, are written policies designed to control drug-using behaviors. The aggressive response to drug-using behaviors, however, is a relatively modern phenomenon in the United States. A series of early American drug laws precipitated current efforts to control drug-related behaviors. These laws included the Pure Food and Drug Act of 1906, the Harrison Narcotics Tax Act of 1914, and the Marijuana Tax Act of 1937. Between the early 1900s and 1969, hundreds of federal drug laws were passed in the United States.