If you're only wondering about gambling, then I can easily tell you why the gambling age is 21. When you enter a casino, you are allowed as many free drinks as you want. The more drunk you get, the more likely you are to stay and gamble.
If the gambling age is 21, then you don't have card people who come up to the bar for drinks. this makes it MUCH quicker to get drinks out to your patrons faster.

If you're talking about why the drinking age is 21, then I'm clueless.
If the gambling age is 21, then you don't have card people who come up to the bar for drinks. this makes it MUCH quicker to get drinks out to your patrons faster.
If you're talking about why the drinking age is 21, then I'm clueless.