Just to make it easy as the law views and adult at 18 and they can die for this country, vote, and go to prison for life. The age should be 18 only because you can do the rest of those things at 18 and it would be easier to change then then to change all the rest. 18 is too young i would think proper age would be 25.
Nineteen is a reasonable age
I use to think that 19 was o.k., and then I witnessed a drinker become a drunk at the age of 19, I tend to lean to the 21 age, maybe at 20, that would be o.k.
I think 21 unless you are a soldier and then you can drink on base at the age of 18. If they can put their lives on the line we should let them have a drink or two or whatever.