Andrew Jenson was an assistant Church Historian and Recorder for The Church of Jesus Christ of Latter-day Saints. He served under Franklin D. Richards from 1897 to 1899. From 1899 to 1900 he was acting Church Historian and Recorder. He then served as an assistant to Anthon H. Lund from October 1900 to March 1921, and then under Joseph Fielding Smith from April 1921 until 1941. He died on November 18 of that year.
Jenson, born Anders Jensen, on December 11, 1850, in Torslev parish, Hjorring, Denmark. He was four years old when his parents joined the Church. He was baptized on February 2, 1859. He left Denmark in 1866 via the ship Kenilworth and arrived in New York on July 16, 1866. He came to Utah Territory with the Andrew H. Scott company and arrived on October 8, 1866. In Utah he anglicized his name.
He served several missions for the Church—three to the Scandinavian Mission, two to the Eastern States Mission, one to the British Mission, one to the Southern States Mission, and one to the Danish Mission. He presided over the Danish Mission from January 1909 to July 1912.
In 1886, Jenson began working part-time for the Church of Jesus Christ. His assignments included conducting interviews and gathering photographs, historic documents, and other documentation during a trip to historic Church sites in the eastern United States. He also gathered similar documents from various stakes and missions throughout the church, which led to the writing of a manuscript history for each ward and stake. Jenson was appointed as a full-time Assistant Church Historian in 1897.
During his time in the Church Historian's office, Jenson was a prolific writer, presenting the history of the Latter-day Saints from an orthodox perspective. He was also a remarkable archivist of historical material and continued to collect records and diaries for the Church Historian's office. He compiled the four-volume Latter-day Saint Biographical Encyclopedia and assisted with the compilation of the Journal History of the Church.
He collected all the records he could find concerning the Mountain Meadows massacre. This archive including his own field notes, excerpts of witnesses' diaries, affidavits, newspaper reports, and the transcriptions from the Church's internal investigations. Many participants in the massacre were granted complete confidentiality for the contents of these interview transcriptions. These files were closed to the public and were not available for use by historians until Latter-day Saint historians Ronald W. Walker, Richard E. Turley Jr., and Glen M. Leonard were granted access and in August 2008 published Massacre at Mountain Meadows through Oxford University Press.