Marquardt is a member of a community of scholars critical of the
Latter Day Saint Movement. In 1974, he published for the first time an
1831 Joseph Smith revelation that in time Mormons would intermarry with
Lamanites to create a white, just race. The
Book of Abraham has been a particular focus area of his research. The Tanners obtained an unauthorized copy of a
microfilm strip containing images of the
Kirtland Egyptian Papers in 1966, and with Marquardt's help published them for the first time as ''Joseph Smith's Egyptian Alphabet & Grammar''. The Tanner publication was revised and updated by Marquardt in 1981. Marquardt added a critical apparatus and some interpretive material.
Collaboration with Wesley Walters He was a collaborator with
Wesley P. Walters, and made some of the first critical arguments for a different timeline of early
Mormonism. Specifically, they argued that the
Joseph Smith family did not move to Manchester until after 1820, and that the religious excitement Smith spoke of in his 1838
first vision account did not occur until 1823–1824. They also were among the first to argue that the
Church of Christ was founded in
Manchester, New York instead of
Fayette, New York as is noted in the official history of the LDS Church. ==Mark Hofmann relationship==