In 1937 they passed a national ban on marijuana. Strict constitutionalists opposed the ban on the grounds that the weed grown and consumed within a state was not the business of the federal government. But they were overruled and a national ban on cannabis remains in effect to this day, even as states legalize it.
Contrast this with Canada. Our friends in the Great White North played around a bit with Prohibition around the time we did, but only on a province-by-province basis.
Once the Noble Experiment got going below their southern border, the Canadians took up the role of liquor producer and made a fortune running booze to the states.
That was duly noted by perhaps the most prominent critic of Prohibition, H.L. Mencken, who famously said, "Congress consists of one third, more or less, scoundrels; two thirds, more or less, idiots; and three thirds, more or less, poltroons."