The first jurisdiction in the United States of America to adopt laws against drunk driving was New York in 1910, with California and others following. Early laws simply prohibited driving while intoxicated, with no specific definition of what level of inebriation qualified.

In the US, most of the laws and penalties were greatly enhanced starting in the late 1970s, and through the 1990s, largely due to pressure from groups like Mothers Against Drunk Driving (MADD) and Students Against Drunk Driving (SADD). These organizations — MADD in particular — are also widely cited for getting the drinking age raised to 21 in those states where it had once been lower. Also during this era, enforcement of drunk driving laws became a priority for police for the first time.

• Alcohol Calculations