Regarding my point that consumption levels had dropped by the 1850s when
the first wave of prohibition arrived, the statistics on the estimated
level of consumption are nicely summarized in Lender and Martin's
DRINKING IN AMERICA (1982), Appendix on p. 196-197.  These are estimates
but seemingly the best thing to go on.
 
The consumption rate stood at an all time high in 1830, at 7.10 gallons
of absolute alcohol per person that year.  By 1840, consumption had
dropped to 3.10 gallons, and in 1850 it was down to 2.10.  See also
Zimring and Hawkins, THE SEARCH FOR RATIONAL DRUG CONTROL (1992), 52-56,
for a very interesting discussion ofthis and why it seems that
prohibitionistviews have enjoyed their greatest success at times when use
rates have been low.  Think about how this corresponds with the
experience of illicit drugs too (the low use rates of marijuana in the
1950s combined with heavy punishments and the peak of tolerance in the
late 1970s when use rates were at their highest).
 
Mike Martin
Temple University