This sign was photographed posted on the door of a restaurant.  Although it is from Texas, it could have been taken almost anywhere in the US. Legal drinking age is still 21 in most (if not all) states of the US, which means that adults aged 18 to 21 may legally vote or join the armed forces and go to war, but they cannot legally drink any alcohol, not even a bottle of beer! This seeming absurdity does not seem to bother the public opinion in the US very much.