Mark Twain wrote a column in July of 1867 bemoaning the “compulsory temperance” movement then gaining ground in Massachusetts: “Prohibition only drives drunkenness behind doors and into dark places, and does not cure it or even diminish it.” The federal government would test that proposition starting 100 years ago in January. Perhaps surprisingly, historians still debate whether the 18th Amendment really improved public health. Some note that drinking fell during the nearly 14 years of Prohibition; others say it just gave folks a thirst for hard liquor, which was readily bootlegged. In any case, alcohol consumption is higher today than it was in 1919.