The Martin family came to Utah in either 1852 or 1853. A child was born in Council Bluffs, Iowa in April 1852, but the first documentation to place them in Utah is the birth of another child 13 July 1854 in Salt Lake City, which was prior to the arrival of that season's emigration. Further research is needed to narrow the year of their travel and provide the name of the company they were with. One family record suggests they left Iowa in 1852 and arrived to Utah in October 1852 with William's brother, Josiah, and his family.
Brigham's death date is confirmed by his death certificate and Find A Grave website.