Before the death of Prophet Joseph many had apostatized. The Saints were not so well established in doctrine as they are today, and some were led astray by the pretensions of prominent men who were disposed to leave the Church and follow their own course. The Twelve Apostles stood next in authority to the Presidency of the Church by the order pointed out in the revelations of God and at the time when Sidney Rigdon was asserting his claims to the guardianship of the Church, President Young stood up to address the Saints. A remarkable manifestation of God's power took place. President Young was transfigured before the people. He appeared to increase in height and in form of his face and body to the exact personal appearance of the Prophet Joseph Smith. When he spoke his voice was as that of the martyred Prophet. People who were present on that occasion say that if their eyes had been closed when he arose from his seat they would have believed the speaker to be none other than the Martyr. Truly the mantle of Joseph had fallen upon Brigham, and while Joseph had received all the keys of the priesthood, he had bestowed them upon the Twelve, also the revelations upon which to build the Church of Christ. President Young truly built upon these revelations during his entire administration. In 1849, at Winter Quarters, he was sustained as President of the Church by the unanimous voice of the priesthood, Heber C. Kimball and Willard Richards then being chosen Counselors and so endorsed by the voice of the Church thereafter at general conferences during the remainder of their lifetimes. President Young presided over the Church as the senior Apostle for thirty-three years, five years in connection with the Twelve and twenty-eight years in the Presidency.