In the late 1850s, he became involved in a court case as the executor of an estate, which led to his expulsion from the church and the development of a separate group. (Read more tomorrow)
In late August or early September, 1863, he was interrupted by a group of Confederates who had come to seize horses from his barn. According to a letter written by B.F. Moomaw shortly after the event: A man was discovered about to take his riding horse. He approached toward him and when coming pretty near, the man ordered him not to approach but John still advanced expostulating with him and finally took hold of the horse when he shot him through the abdomen and then clave his skull with the butt of the gun. So ends his eventful life and it is thought will end his church.
And thus, Bowman became one of the Brethren victims of the Civil War.
Source: The Brethren Encyclopedia