Is there any systematic study of minimum drinking age in the USA before
National Prohibition?  Any comparative dates for other Western countries in
the nineteenth and early twentieth centuries? I assume that in the USA the
minimum legal drinking age was 21, but I have no evidence for it.  By the
way, I know that in recent times before the principle of equal rights for
men and women had been accepted, there sometimes were different minimum ages
for their drinking (as for their right to marry without parental consent).
 I vaguely recall that Oklahoma (?) may have set a minimum drinking age for
men at 21 and for women at 18, paralleling the marriage law.