The first third party in U.S. history, the Anti-Masonic party was formed in 1827 to counter the alleged subversion of public institutions by the Freemasons. Hostility toward the Masons erupted following the disappearance and suspected murder (1826) in upstate New York of William Morgan, the author of a purported expose of the Masons.

The party rapidly gained followers, and in 1831 it held a national nominating convention in Baltimore--the first time that practice was followed. However, its presidential candidate, William Wirt, carried only one state (Vermont) in 1832, while Andrew Jackson, a Mason, won overwhelmingly. The party merged with the Whigs after 1838.