History speaks for itself
For almost 40 years, most states voluntarily set their minimum drinking age law at 21. In the late 60s and early 70s, 29 states lowered their drinking age to more closely align with the newly reduced military enlistment and voting age.
The results were immediate -- drunk driving crashes and alcohol-related fatalities increased significantly in those states.1 And not just in those states -- "blood borders", where young people would drive to a state with a lower drinking age, drink, and crash on their return, cropped up across the country. As a result, 16 states had increased their drinking ages back to age 21 by 1983.
Confronted by the failure of the 18 minimum drinking age, the President Commission on Drunk Driving recommended establishing a national 21 minimum drinking age. President Reagan agreed and on July 17, 1984, he signed into law the Uniform Drinking Age Act mandating all states to adopt 21 as the legal drinking age within five years. By 1988, all states had set 21 as the minimum drinking age.
Since that time, the 21 minimum drinking age law has saved about 900 lives per year as estimated by the National Traffic Highway Administration (NHTSA). In short, there are more than 25,000 people alive today because of the 21 minimum drinking age law in every state.2-3
Additionally, underage drinking rates also fell and continue to fall. From 1991 to the present, annual use of alcohol among 8th, 10th, and 12th graders has dropped 56%, 33%, and 18%, respectively.4
1. Shults, Ruth, et al. "Reviews of Evidence Regarding Interventions to Reduce Alcohol-Impaired Driving." American Journal of Preventive Medicine 21(4S) (2001): 66-88.
2. National Highway Traffic Safety Administration. "Lives Saved in 2008 by Restraint Use And Minimum Drinking Age Laws." DOT HS 811 153. June 2009.
3. National Highway Traffic Safety Administration. "Traffic Safety Facts 2008: Young Drivers." DOT HS 811 169. 2009.
4. Johnston, L. D., O'Malley, P. M., Bachman, J. G., & Schulenberg, J. E. Monitoring the Future national survey results on drug use, 1975-2012. Volume I: Secondary school students. Bethesda, MD: National Institute on Drug Abuse, 2012.