The Second Advent Movement
From the article:
The year 1844 is familiar to Seventh-day Adventists as the year that a group of Millerites mistakenly expected the Second Advent of Jesus Christ.
On October 22, 1844, these men, women, and children longingly expected to see their Saviour and their loved ones that had passed away. They waited for the signs of Christ’s appearing. But as they watched the sun slowly slide below the horizon after a long day of waiting and watching, their hope slipped from them. As night fell, they faced their dashed expectations with bitter disappointment. Many turned their backs on God when He didn’t deliver on their understanding of Scripture. But some did not give up…..