John Kline is perhaps the most well-known of the horseback preachers who traveled widely to keep the Brethren connected as they moved westward on the frontier. Living in Virginia, Kline traveled through what is now West Virginia, Kentucky, Tennessee, and Ohio, preaching, holding council meetings, presiding over love feasts, and baptizing. Nearly every spring and fall he would make a tour to the Brethren in the "West". His ministry carried him perhaps 100,000 miles during his lifetime, and those mostly by horseback.
John Kline lived at a time when the Brethren suffered under the Civil War. Both the Federal and Confederate governments tried to draft the Brethren into military service, but the pressure was especially strong from the South. John Kline and others wrote to government officials asking for some kind of exemption. They explained that Brethren support the government in every way possible, but cannot support it when its requirements violate the commands of God in the New Testament. Through these efforts the governments of both North and South allowed Brethren to pay a fee ($500 in the South) for the privilege of exemption from the army. However, many Brethren were persecuted for their beliefs, and some were killed.
In the spring of 1864 John Kline insisted on traveling through the military fronts of the Civil War to go to Indiana, where he was to serve as moderator of Annual Conference. He knew that many people in Virginia were angered by his opposition to slavery, his work to exempt the Brethren from the army, his willingness to give medical assistance to anyone who was ill, and his travels to churches in both the North and the South. Some suspected him of spying for the North. He told his friends at the Indiana Annual Conference that they would perhaps not see him again. Shortly after the long trip home to Virginia, he was taking his horse Nell to be shod when a shot rang out. John Kline fell dead from his horse, a martyr to Christ's way of peace.
John Kline stated very clearly: The Brotherhood is a unit, heart and hand against arms-bearing.
Source: A Self-Instruction Guide through Brethren History, Donald E. Miller