The Christian Church (Disciples of Christ) is a mainline Protestant Christian denomination in the United States and Canada. The denomination started with the Restoration Movement during the Second Great Awakening, first existing during the 19th century as a loose association of churches working towards Christian unity, then slowly forming quasi-denominational structures through missionary societies, regional associations, and an international convention. In 1968, the Disciples of Christ officially adopted a denominational structure at which time a group of churches left to remain nondenominational.