The drinking age used to vary by states . Some had it at 18 and some at 21 . The problem with this was that what would happen is college students would drive to the states where it ' s 18 and drive drunk for hours back home . This caused lots and lots of drunk driving deaths . This still happens today with dry counties people drive to the wet counties and drive drunk all night back to the dry counties . So Mothers Against Drunk Driving campaigned to get the drinking age nationally raised to 21 . The states could vote on this but if they didn ' t raise the drinking age to 21 , their federal highway funding would be cut off . Louisiana was the last holdout . Nationally , the voting age used to be 21 as well . As for people arguing that lowering the driving age would reduce drunk driving , the data doesn ' t suggest such . Only 17 % of drunk drivers in fatal crashes are found to be underage . The most common demographic for drunk drivers are 2124 drvfactsheet . html . In fact , stricter enforcement over the years has actually lowered the amount of kids drinking and driving . The reason why Europeans can get away with a low drinking age is because they don ' t have a car culture like we do . They don ' t have nearly as many teenagers driving . They also don ' t have the same party culture at colleges .