Widtsoe married
Leah Dunford, a daughter of
Susa Young Gates, who was a daughter of LDS Church
president Brigham Young. Their first child, Ann Gaarden Widtsoe, was born in Germany. The couple had eight children, but only three lived to adulthood. Widtsoe worked closely with his wife and mother-in-law on a biography of Young. Widtsoe also edited a book containing Young's significant teachings. Widtsoe was also the lead compiler of
Gospel Doctrine, a collection of sermons and teachings of LDS Church president
Joseph F. Smith. Widtsoe and his wife authored
The Word of Wisdom: A Modern Interpretation, a book which advocates the incorporation of healthy eating habits into the
Word of Wisdom. Widtsoe wrote
A Rational Theology as Taught by the Church of Jesus Christ of Latter-day Saints, which has been cited by later LDS authors such as
J. Reuben Clark. He also wrote
Evidences and Reconciliations, which was a compilation of his
Improvement Era writings, answering common questions on matters of faith. In this work, Widtsoe acknowledges that there are multiple interpretations that Latter-day Saints can hold on certain issues. One example is his explanation of the time involved in the creation of the earth: he indicated that faithful Latter-day Saints could hold the "six-day", "six-thousand-years", or the "undefined-period" interpretations of the creation. Although Widtsoe focused on explaining the rationale for the "undefined-period" interpretation, he did not belittle the other two or state that they were unorthodox. In 1939, Widtsoe published
Priesthood and Church Government. His work,
The Message of the Doctrine and Covenants, was edited by son-in-law
G. Homer Durham, and published after Widtsoe's death. Widtsoe wrote
Seven Claims of the Book of Mormon: A Collection of Evidences with Franklin S. Harris, Jr. Widtsoe wrote a biography of
Joseph Smith entitled
Joseph Smith: Seeker After Truth Prophet of God. It was published in 1951, and reprinted by
Bookcraft in 1957. Widtsoe also wrote
Joseph Smith as Scientist: A Contribution to Mormon Philosophy, published by the
Young Men's Mutual Improvement Association in 1908. In 1944, his essay, "The Divine Mission of Joseph Smith", was included in
Handbook of the Restoration published by Zion's Printing and Publishing Company in
Independence, Missouri. Non-religious books by Widtsoe include
Dry-Farming: A System of Agriculture for Countries Under a Low Rainfall (New York: MacMillan, 1920) and ''Dodge's Geography of Utah''. Widtsoe wrote two autobiographies. The first,
In the Gospel Net, largely focused on his mother's conversion to the LDS Church. The second,
In a Sunlit Land, told the story of his later life, and included explanations of his educational philosophy. ==Hymns==