Nephi is seen in Iowa on the 1850 Census in Iowa, which was enumerated on 4 October 1850, which was past that year's emigration season. First documenation to place him in Utah is a rebaptism in the Utah Stake City Branch on 1 January 1852, so he must have traveled in 1851. Further research is needed to identify the name of the company he traveled. with.
His birth date is verified in Payson Ward records at the time of another rebaptism on 14 December 1855.