Emerging during the Second Great Awakening, the Millerites were followers of the millenarian teachings of a self-made preacher named William Miller (1782–1849). Miller, who was born in Pittsfield, Massachusetts, was an unlikely candidate to lead a large religious movement. Miller, a deist for a time, had experiences in the War of 1812 that led him to a more active religious life.

After moving to Low Hampton, New York, and attending a Baptist church, he took a strong interest in the Second Coming of Christ. Miller studied the Bible and constructed a timeline for what he believed were the rapidly approaching “End Times.” Hesitantly, he stated that end would come sometime between 21 March 1843 and 21 March 1844.

His writings were detailed and meticulous, focusing on the Book of Daniel and the Book of Revelation. After many years of failing to convince ministers and preachers of the accuracy of his predictions, Miller reluctantly took to preaching himself in 1833. In 1838 he gained a highly skilled and valuable follower named Joshua V. Himes.

A hardworking abolitionist, Himes helped to manage Miller’s affairs and published several Adventist newspapers such as the Midnight Cry and Signs of the Times, which proclaimed Miller’s message. The papers sought to link current events to Miller’s timeline while warning the public about the coming apocalypse. Only with the help of Himes did Millerism attract a large following.

The Millerites, although often assumed to be from the poor and lower classes, actually came from all classes, tended to be from a rural background, and had a variety of professions and religious affiliations.

Miller encouraged his followers to remain with their denominations for most of his career. Unlike previous millenarians, the Millerites had no real political agenda, and they focused entirely on the imminent Second Coming of Christ.

It is unclear exactly how many Millerites there were, but some estimates place the figure at 50,000 committed followers with many thousands more cautiously interested and lukewarm followers. One of Miller and Himes’s most successful methods for recruiting followers was their use of the traveling “Great Tent” for revival meetings.

As the movement grew, other meetings began to occur on a regular basis throughout the northeastern United States, and especially in New York State’s “Burned-Over District” (so named for the repeated waves of religious revival which “burned over” the area). As 1843 approached the movement became more cohesive and suffered more critical scrutiny at the hands of the press.

Horace Greeley’s Tribune spent an entire issue attacking Millerism. The competency and motivations of the movement’s leaders were questioned. Some of the more radical elements within the Millerites responded by declaring their opponents to be Antichrists and calling for separation from existing churches and denominations.

As the “final year” came and passed, the Millerites felt a deep sense of disappointment and uncertainty. William Miller sent out a message to his followers declaring that he had been mistaken about the date, but he still felt that the end of time was approaching rapidly. While Miller and Himes continued preaching, another Millerite minister, Samuel Snow, set a new date for the Second Coming.

Snow stated that Christ would return on the Hebrew Day of Atonement—22 October 1844. Although Miller was reluctant to select another date for the return of Christ, he was pressured into acknowledging Snow’s date as a possibility. There was soon more anticipation for the new prediction than there had been for the previous one.

Popular images and writings have portrayed the Millerites as dressing in white robes and climbing to hilltops and rooftops on 22 October 1844, although this has never been verified. The failure of Snow’s prediction, now known as the Great Disappointment, brought a new wave of criticism from the press and charges of dishonesty. Many urban intellectuals viewed Millerism as a form of insanity.

Amariah Bringham, head of Utica State Lunatic Asylum, stated that even though most Millerites were normal, their teachings were a threat to mental health and to future generations. Only about 170 Millerites were institutionalized in the United States, but the numbers didn’t prevent Millerism from becoming the stereotype for religious mania and delusions.

Miller and Himes never again advocated an exact date for the Second Coming. They instructed their followers to live as if every day could be the end. The movement soon broke into groups and factions, with the most prominent being the Seventh Day Adventists.