Alexander Campbell was an early leader in the Second Great Awakening of the religious movement that has been referred to as the Restoration Movement, or Stone-Campbell Movement. The Campbell wing of the movement was said to begin with his father Thomas Campbell's publication in 1809 in Washington County, Pennsylvania, of The Declaration and Address of the Christian Association of Washington.
Thomas Campbell was a Presbyterian minister important in the Second Great Awakening of the United States. Born in County Down, northern Ireland, he began a religious reform movement on the American frontier. He was joined in the work by his son Alexander Campbell. Their movement, known as the "Disciples of Christ", merged in 1832 with the similar movement led by Barton W. Stone to form what is now described as the American Restoration Movement (also known as the Stone-Campbell Restoration Movement).