In 1818, Abraham Snethen, the “barefoot preacher,” witnessed the jerks while preaching to a congregation of New Light “Christians” in Clay County, Kentucky. For the complete text of Snethen’s autobiography, see Paul Woehrmann, ed. “The Autobiography of Abraham Snethen, Frontier Preacher,” Filson Club Historical Quarterly 51 (1977): 315–335.

…now I left for cincinati again and on my way heard of the New light Presbytarians and Marshallites which is the Chrystian Church now and heard all sort of bad reports a bout them they said that they would trac the Devil up trees and bark at him about this tim the bodily exercise of falling and jerks and other exercises such as laughing they would fall and lay for hours and appear entierly [?] others jerk backwards and forwards with somuch force that a ladys hair wold crack like a wip it apeard almost all denominations and had a good affeit for the wickedest of men would take it as well as any and hardly ever let them go untill they out relijious….

Source

Paul Woehrmann, ed. “The Autobiography of Abraham Snethen, Frontier Preacher,” Filson Club Historical Quarterly 51 (1977): 325.