Ellen WhiteFounder of the Seventh-day Adventist movement, owing a lot to the prophecies of William Miller and others.
William Miller 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 Jehovah's 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.