The party was formed in Hancock County to oppose the political power Joseph Smith held in Nauvoo, Illinois, as the mayor of the city, head of the Nauvoo Legion, and prophet to the city's Latter Day Saint residents.
The party was organized in July 1841 by Thomas C. Sharp, editor of the Warsaw Signal.
The meeting also resolved "[t]hat it is expedient to hold a county convention, for the purpose of nominating candidates for the offices of School and County Commissioners, in opposition to Mormon influence and dictation.
[4] The party continued its existence until it gradually died out after June 1844, when Joseph Smith was killed by an armed mob and the majority of Latter Day Saints subsequently made it known that they intended on leaving Illinois.
The five men who were tried and acquitted of murdering Smith—Sharp, Grover, Mark Aldrich, Jacob C. Davis, and Levi Williams—were all members of the Anti-Mormon Party.