While in Denmark, Jenson established a monthly periodical called Morgenstjernen, which he continued to publish in Utah after his return.

[2] 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 was also closely involved with the compilation of the Journal History of the Church, which has been described by Utah historiographer Gary Topping as ...an immense scrapbook compilation consisting of several hundred volumes of various historical records (in its later years mostly newspaper clippings) documenting Mormon history from the beginning of the church until well into the twentieth century.

This archive including his own field notes, excerpts of witnesses' diaries, affidavits, newspaper reports, and the transcriptions from the LDS Church's internal investigations.

However, in August 2008, LDS historians Ronald W. Walker, Richard E. Turley Jr., and Glen M. Leonard published Massacre at Mountain Meadows through Oxford University Press.