William MillerWilliam Miller was a farmer from upstate New York who was a veteran of the War of 1812. He started telling people in 1831 that the Biblical prophecies described in Revelation had yet to transpire. And if that wasn't enough, he revealed that they were about to.
Basically, Miller singlehandedly revived the "End Is Near" mania. Lots of other religious figures began making similar apocalyptic claims. Miller drew a large following, and in 1840, he finally announced a specific range of dates for the second coming of Jesus Christ. He said it would occur sometime between March 21, 1843 and March 21, 1844.
When March 22, 1844 arrived without any perceptible return of Christ, it was kind of a problem for Miller. Thousands of followers had given away their possessions in anticipation of the big day. Not good. But then one of Miller's followers realized that his calculations had been off by one year, because he neglected to count the BC to AD rollover. So he revised the date to October 22 and tried again.
In October, of course, the same damn thing happened. Except this time, there weren't any arithmetic errors to blame. Upwards of 100,000 Millerites had expected to finally meet God Jr. Many of them dressed in white robes and climbed up on roofs and hilltops. But the chosen night came and went. The milestone would come to be known as the Great Disappointment of 1844.
According to one believer: "The world made merry over the old Prophet's predicament. The taunts and jeers of the 'scoffers' were well-nigh unbearable." Nevertheless, Miller hung tough. The following month, he expressed his never-say-die attitude in a letter:
Although I have been twice disappointed, I am not yet cast down or discouraged ... My hope in the coming of Christ is as strong as ever. I have done only what after years of sober consideration I felt a solemn duty to do ... I have fixed my mind upon another time, and here I mean to stand until God gives me more light. And that is Today, TODAY, and TODAY, until He comes, and I see HIM for whom my soul yearns.
William Miller finally did see "HIM" when he died on December 20, 1849. Almost overnight, the remnants of his church splintered over doctrinal differences. This fragmentation ultimately gave rise to a variety of denominations, including the Jehovah Witnesses and the Seventh-Day Adventists.
In the 20th century, an offshoot of the Seventh-Day Adventists updated Miller's prophecy by claiming a Biblical ETA of April 22, 1959. (Yahweh's bastard child was a no-show yet again.) This group, calling itself the Davidian Seventh-day Adventists, broke into two pieces in the resulting schism. One product of this fission decided to call themselves the Branch Davidians.