Mitt Romney is not the first Mormon to run for President. That distinction belongs to Joseph Smith, who was in fact the first Mormon. Smith, who founded what became the Church of Jesus Christ of Latter-day Saint, announced his candidacy in January 1844 as a Mormon on a platform based on tenets of the Mormon religion. His announcement was a fateful decision for him and the future of his religion, and a fascinating moment of forgotten American history.
Used availability for Thomas B Allen's The First Mormon Candidate