This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
William Miller, born in Pittsfield, Massachusetts in 1782, was a Baptist lay preacher in upstate New York whose independent study of the book of Daniel, chiefly the twenty three hundred day prophecy of Daniel 8:14, led him by 1818 to a specific conclusion: that Christ would return to earth and cleanse it by fire sometime between 1843 and 1844, a conclusion he reached through his own private study rather than any claimed revelation.
Miller kept that conclusion largely private for over a decade before beginning to preach it publicly in 1831. Over the following ten years a large interdenominational following gathered around his calculation, spread in significant part through the publishing efforts of Joshua Himes, whose periodicals and pamphlets carried Miller's reading of Daniel far beyond what one traveling preacher could have reached through preaching alone, giving a regional lay preacher's Bible study a national audience.
By the early 1840s that following, later known as the Millerites, had grown into a substantial and organized interdenominational movement, drawn from many existing churches by a shared expectation built entirely on Miller's own chronological reading of a single prophetic text rather than on any new revelation he claimed to have received, a movement whose size and organization would make what followed in 1843 and 1844 a genuinely public event rather than a private disappointment.