Re: Also . . .
The drinking thing is for "hard liquor". Beer and wine coolers in some states are as low as 18 and 19.
In the military, however, and with parental consent, you can join up at 17 and kill people, but the military won't let you drink ANY alcohol beverages until you're 21, regardless of what state you're in (circumstances [knowing who you can and cannot drink with] have bent this law an unspecified number of times).
Dan