Though a part of the St. George Temple was dedicated on Jan. 1, 1877, the full dedication would come later, according to "A Comprehensive History of the Church," Vol. 5, pp. 506-507.
"By April the whole structure was ready for dedication and accordingly the annual conference of the Church was appointed to convene at that place, and on the sixth of April the whole structure was dedicated, Daniel H. Wells offering the dedicatory prayer. The presidency of the Church and most of the apostles were present, and very many prominent elders and a large number of the Latter-day Saints from the northern settlements were there."
The book noted that President Brigham Young returned to Salt Lake City through Manti, Utah, where he dedicated the temple site there.
It said that he also directed the dedication and groundbreaking for the temple in Logan, Utah, in May.