Wendy McElroy remembers one of the greatest publishing hoaxes of the 20th century:
On December 28, 1917, Mencken published the article “A Neglected Anniversary” in the New York Evening Mail. He announced that America had forgotten to celebrate the seventy-fifth anniversary of the modern bathtub, which had been invented on December 20, 1842 in Cincinnati, Ohio. “Not a plumber fired a salute or hung out a flag. Not a governor proclaimed a day of prayer,” Mencken lamented. He proceeded to offer an informal history of the US bathtub, with political context. For example, President Millard Fillmore had installed the first one in the White House in 1851. This had been a brave act since the health risks of using a bathtub were highly controversial within the medical establishment. Indeed, Mencken observed, “Boston early in 1845 made bathing unlawful except upon medical advice, but the ordinance was never enforced and in 1862, it was repealed.”
The actual political context was somewhat different. America had entered World War I several months before. The media was now rabidly anti-German and pro-war. Mencken was of German descent and anti-war. Suddenly, he was unable to publish in his usual venues or on his usual subjects. Thus, Mencken – a political animal to the core – turned to non-political writing in order to publish anything: A Book of Prefaces on literary criticism (1917); In Defense of Women on the position of women in society (1918); and The American Language (1918). But he was effectively shut out of the most important event in the world, the one about which he cared most.
Mencken did not just get mad; he got even. “A Neglected Anniversary” was a satire destined to become a classic of this genre. In his article, Mencken spoke in a tone of mock-reason, which was supported by bogus citations and manufactured statistics. His history of the bathtub was an utter hoax set within the framework of real history. The modern bathtub had not been invented in Cincinnati. Fillmore had not introduced the first one into the White House. The anti-bathtub laws cited were, to use one of Mencken’s favorite words, “buncombe.”
[…]
Mencken remained silent about the hoax until an article titled “Melancholy Reflections” was published in the Chicago Tribune on May 23, 1926, eight years later. It was Mencken’s confession and an appeal to the American public for reason. His hoax had gone bad. “A Neglected Anniversary” had been reprinted hundreds of times. Mencken had received letters of corroboration from some readers and requests for more details from others. His history of the bathtub had been cited by other writers and was starting to find its way into reference works. As Mencken noted in “Melancholy Reflections,” his ‘facts’ “began to be used by chiropractors and other such quacks as evidence of the stupidity of medical men. They began to be cited by medical men as proof of the progress of public hygiene.” And, because Fillmore’s presidency had been so uneventful, on the date of his birthday calendars often included the only interesting tidbit they could find: Fillmore had introduced the bathtub into the White House. (Even the later scholarly disclosure that Andrew Jackson had a bathtub installed there in 1834 did not diminish America’s conviction that Fillmore was responsible.)
Upon confessing, Mencken wondered if the truth would renew the cry for his deportation. The actual response: Many believed his confession was the hoax.
It took a bit longer for the team to get 
