A few examples of early statements:
1. "Why therefore do we not reject every care of earthly actions and prepare ourselves for the meeting of the Lord Christ, so that he may draw us from the confusion, which overwhelms all the world? . . . For all the saints and elect of God are gathered, prior to the tribulation that is to come, and are taken to the Lord lest they see the confusion that is to overwhelm the world because of our sins." Source: Pseudo-Ephraem, On the Last Times, the Antichrist, and the End of the World, section 2, translated by Cameron Rhoades, produced by The Pre-Trib Research Center. See Timothy J. Demy and Thomas D. Ice, "The Rapture and an Early Medieval Citation, Bibliotheca Sacra, (Vol. 152, No. 607; July-September 1995), pp. 306-17. Reprinted in Thomas Ice and Timothy J. Demy, The Return: Understanding Christ's Second Coming and the End Times (Grand Rapids: Kregel, 1999), pp. 55-66.
This text has of course been 'critiqued' by Dr. Robert Gundry of Westmont College, a leading posttribulationist, but Ice and Demy, in their book The Return, pp. 67-73 thoroughly discredited Gundry so the text stands.
2. Morgan Edwards - wrote about his pretrib beliefs in 1744 and later published them in 1788. Source: Morgan Edwards, Two Academical Exercised on Subjects Bearing the following Titles; Millennium, Last-Novelties (Philadelphia: self-published, 1788). See Thomas Ice, "Morgan Edwards: Another Pre-Darby Rapturist," Pre-Trib Perspectives (Vol. II, No. 4; Sept/Oct 1995), pp. 1-3.
Morgan stated:
II. The distance between the first and second resurrection will be somewhat more than a thousand years.
I say, somewhat more-, because the dead saints will be raised, and the living changed at Christ's "appearing in the air" (I Thes. iv. 17); and this will be about three years and a half before the millennium, as we shall see hereafter: but will he and they abide in the air all that time? No: they will ascend to paradise, or to some one of those many "mansions in the father's house" (John xiv. 2), and disappear during the foresaid period of time. The design of this retreat and disappearing will be to judge the risen and changed saints; for "now the time is come that judgment must begin," and that will be "at the house of God" (I Pet. iv. 17) . . . (p. 7; The spelling of all Edwards quotes have been modernized.)
Those are just 2 sources that seriously pre-date 1830. To continue to promote that it wasn't taught prior to the 19th century is disingenuous at best.
I mean those who reject the rapture are still not going to believe in it necessarily on the basis of these texts, but anyone who is honest in their research will have to revise their statements by at least a 1,000 years.
To not do so and continue to propagate a lie that has been disproven speaks volumes about their true spiritual state. JMO.
WELL PUT.