"Anti-Masonic Movement, in the history of the United States, popular movement based on public indignation at and suspicion of the secret fraternal order known as the [those Particular] Masons, or Freemasons. Opponents of this society seized upon the uproar to create the Anti-Masonic Party. It was the first American third party, the first political party to hold a national nominating convention, and the first to offer the electorate a platform of party principles. The movement was ignited in 1826 by the mysterious disappearance of William Morgan, a bricklayer in western New York who supposedly had broken his vow of secrecy as a".