The Great Disappointment in the Millerite movement was the reaction that followed Baptist preacher William Miller's proclamations that Jesus Christ would return to the Earth in 1844, what he called the Advent. His study of the Daniel 8 prophecy during the Second Great Awakening led him to the conclusion that Daniel’s “cleansing of the sanctuary” was cleansing of the world from sin when Christ would come, and he and many others prepared, but October 22, 1844 came and they were disappointed. However, it paved the way for the Adventists who formed the Seventh-Day Adventist Church. They contended that what had happened on October 22 was not Jesus’ return, as Miller had thought, but the start of Jesus’ final work of atonement, the cleansing in the heavenly sanctuary, leading up to the Second Coming.
The "sanctuary" did come in 1944. It was the Nauvoo Temple.
Completing the Nauvoo Temple
October 1844, the first General Conference of the church under Brigham Young's direction is held.
Throughout this period, Brigham Young and members of the Twelve kept work on the temple moving. They met frequently with the architect and temple committee and repeatedly invited the members to “gather to Nauvoo with their means” to help build the house of the Lord. In the October 1844 general conference, Brigham Young said, “I believe this people is the best people of their age that ever lived on the earth, the church of Enoch not excepted. We want you to come on with your tithes and offerings to build this Temple.” In response the “Relief Society sisters recommitted themselves to contribute a penny a week per member for glass and nails,” while those of means contributed large sums without which the project would not have progressed. Joseph Toronto handed Brigham Young twenty-five hundred dollars in gold, saying “he wanted to give himself and all he had” to build the kingdom of God. Numerous craftsmen were called to help with the project. By the spring of 1845 the capstone was in position. The workers then assembled the roof and finished the interior. Plans were set for a formal dedication in April 1846.
Rooms in the temple were dedicated as they were completed so that ordinance work could begin as early as possible. General conference convened in the partially finished edifice in October 1845. Brigham Young “opened the services of the day by a dedicatory prayer, presenting the Temple, thus far completed, as a monument of the saints’ liberality, fidelity, and faith, concluding: ‘Lord, we dedicate this house and ourselves, to thee.’ The day was occupied most agreeably in hearing instructions and teachings, and offering up the gratitude of honest hearts, for so great a privilege, as worshiping God within instead of without an edifice, whose beauty and workmanship will compare with any house of worship in America, and whose motto is: ‘HOLINESS TO THE LORD.’”
11 Yea, he magnified himself even to the prince of the host, and by him the daily sacrifice was taken away, and the place of his sanctuary was cast down.
12 And an host was given him against the daily sacrifice by reason of transgression, and it cast down the truth to the ground; and it practised, and prospered.
13 ¶ Then I heard one saint speaking, and another saint said unto that certain saint which spake, How long shall be the vision concerning the daily sacrifice, and the transgression of desolation, to give both the sanctuary and the host to be trodden under foot?
14 And he said unto me, Unto two thousand and three hundred days; then shall the sanctuary be cleansed.