Thomas Campbell (1 February 1763 – 4 January 1854) was a Presbyterian minister who became prominent during the Second Great Awakening of the United States.

[1] Once in America, disagreement arose between Thomas and other Presbyterians over certain points related to Calvinist doctrine and the administration of the Eucharist.

[2]: 117 When their study of the New Testament led the reformers to begin to practice baptism by immersion, the nearby Redstone Baptist Association invited Brush Run Church to join with them for the purpose of fellowship.

"[4]: 80  The essentials he identified were those practices for which the Bible provided "a 'Thus saith the Lord,' either in express terms or by approved precedent.

"[4]: 81  Unlike Locke, who saw the earlier efforts by Puritans as inherently divisive, Campbell argued for "a complete restoration of apostolic Christianity.

First, it provided the idea that Christian unity could be achieved by finding a set of essentials that all reasonable people could agree on.