Cannon returned to Utah in the fall of 1864 and became the private secretary to Brigham Young. At this time he stated that, with the exception of nine months, he had been absent from home for fifteen years in service to the church. Under the tutelage of President Young, Cannon became well acquainted with all aspects of church affairs, and, recognizing the need for appropriate reading material for the youth, established the Juvenile Instructor magazine in 1866. The following year he was called as general superintendent of the Deseret Sunday School Union, a position he held until his death. Later that year, he was appointed to oversee the Deseret News. One of his first decisions as president and editor was to renovate the semiweekly into a daily newspaper named the Deseret Evening News. He left the paper in 1872 when he was elected a Utah delegate to Congress.