In 1962, Larsen was appointed the secretary of the LDS Church Indian Committee. He taught for one year at the Institute of Religion at the University of Utah and then was asked to become president of the church's Texas South Mission. Upon completing this three-year assignment, Larsen taught at the Institute of Religion in Ogden, Utah. In the LDS Church, Larsen has served as a bishop and regional representative. In 1976, Larsen became the editor of all church magazines.
^Lloyd, R. Scott (May 28, 2005). "Historian by yearning' collects, preserves: Elder Marlin K. Jensen is historian/recorder". Church News. Deseret Morning News.
^ abIn 1837 the callings of Church Historian and Church Recorder were separated, but in 1842 these callings were again merged.
^Starting in 1978, the duties of Church Historians fell to the Executive director of the historical department.
^While Larsen was still technically Church Historian until 1997, others succeeded him as Executive Director of the Historical Department, and those men were sometimes referred to as the Official Church Historians.
^In 2005 the callings of Church Historian and Church Recorder was restored.