What states are you allowed to drink alcohol (if you are under 21) under parental supervision/at home.?!
42 states have set their own exceptions to allow underage consumption of alcohol under certain circumstances. Eight states (Alabama, Arkansas, Idaho, Indiana, Kentucky, New Hampshire, Pennsylvania, and West Virginia) and the District of Columbia have no exceptions in their underage alcohol possession or consumption laws.
Check out http://www.alcoholpolicy.niaaa.nih.gov/S…
You can check out states that allow drinking U21 in the home, those that allow it outside the home, and those that don't allow it at all, either on a state by state basis or on a USA wide map.
In the UK (not yet a US State, of course - although the USA was once a British colony ;)) it is legal to drink at home at 5 years of age and over.
Louisiana is one I know of, but there may be more.
Edit: I googled it, and it's only Louisiana.