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's prediction that Christ would return between the spring of 1843 and the spring of 1844, drawn from his reading of Daniel 8:14, culminated in a specific date, 22 October 1844. When that day passed without the expected Second Coming, the failure became known among Miller's own followers as the Great Disappointment, a name the movement gave to its own defining crisis rather than one imposed from outside.
Hiram Edson and other Millerites who lived through the failed date did not abandon the movement afterward; instead they reinterpreted the prophecy itself, arguing that it described Christ entering a heavenly sanctuary in 1844 rather than returning bodily to earth. That reinterpretation, the investigative judgment doctrine, became the theological foundation the surviving Millerites built on rather than a single failed prediction they simply walked away from.
What the Great Disappointment changed for the movement's spread was direction itself: without the reinterpretation Edson and his fellow Millerites worked out in its immediate aftermath, the scattered Sabbatarian Adventist groups the failed date left behind would have had no shared doctrine to organize around, and no path from a single wrong date in 1844 toward the denomination that would organize under it two decades later.