1958 was a close second place drinking low year at 55% as their parents realized "My God, what have we done?" ha ha ha.
Seriously now, 71% drank in 1976, 1977, and 1978, the Baby Boom Bender.
Prior to 1984, many states like Wisconsin had lowered the drinking age to 18 from 21 because the voting age had been changed to 18 in 1971 by the 26th Amendment.
The National Minimum Drinking Age Act of 1984 turned this back the other way again by withholding federal highway funds from states that did not raise their drinking age back to 21, which Wisconsin finally did in 1986. Wisconsin had a tiered system between 1984 and 1986 where the drinking age was 19 for beer and wine and 21 for liquor.
Gallup reports here:
... The highs of 68% to 71% were all recorded between 1974 and 1981. ...
This anthem made its debut in 1985:
