What constituted a man being old enough to belly up to the bar? Usually it was up to the judgment of the proprietor or bartender. It looks like Billy the Kid was hanging out in saloons by the time he was 18. Billy Clanton was doing the same when he was a teenager. They were accepted as adults at that point and so their presence was allowed. I imagine that kids younger than that–those who were on their own, who worked as cowboys–could get in and be served. But that was at the discretion of the saloon.
One other thing–youth alcoholism was a big reason that Prohibition finally was approved. I haven’t seen good figures on it, but a huge number of kids were hooked before they were sixteen. John Wesley Hardin is a good example.
Bartenders were pretty good at judging whether a lad was still wet behind the ears and would act accordingly. Most youths in their early teens were doing men’s work during the Great Depression so you can imagine how it was 50 years earlier.
Come to think of it I know some ranch and farm kids today who act more responsibly than most 25-year-old city boys.
Marshall Trimble is Arizona’s official historian and vice president of the Wild West History Association. His latest book is Arizona Outlaws and Lawmen; The History Press, 2015. If you have a question, write: Ask the Marshall, P.O. Box 8008, Cave Creek, AZ 85327 or email him at email@example.com.