John T. Wilder was an influential nineteenth-century American industrialist, and a successful foundry owner at Greensburg, Indiana, when he enlisted in the Union Army during the Civil War in April 1861. He was quickly promoted to the rank of colonel, and eventually earned the brevet rank of brigadier general. Wilder distinguished himself as the leader of the 17th Indiana Volunteers, aka "Wilder's Lightning Brigade." He was among the first officers from either side to realize the effectiveness of the Spencer Repeating Rifle against the single-shot rifles most soldiers were using. Resourceful and creative in his leadership, Wilder also acted with bravery and distinction during the major battle of Chickamauga in the summer of 1863. This biography also explores Wilder's surrender in the fall of 1862 at Munfordville, Kentucky, when he was in command of a small regiment of fresh recruits surrounded by overwhelming Confederate numbers. Wilder took the unprecedented move of going into the Confederate camp under a flag of truce to seek advice from one of the Confederate generals, leading him to realize surrender was his best, and only, option. After the war, Wilder answered the call Chattanooga, Tennessee, issued for northern investors to relocate to their city. Wilder developed mines across eastern Tennessee and western North Carolina, and dabbled in the hotel and railroad business, as well as politics. He was also heavily involved with getting the Chickamauga Battlefield established as the first National Military Park in the United States.