Fetterman enlisted in the
Union Army on May 14, 1861, in
Delaware, and was promptly commissioned a
first lieutenant. He served with the
US 18th Infantry Regiment throughout the war and was twice
brevetted for meritorious service and gallant conduct, finishing the war as a
lieutenant colonel by brevet. During the
Atlanta campaign in 1864, Fetterman commanded the 2nd Battalion of the 18th US Infantry. This unit was part of
John H. King's 2nd Brigade,
Richard W. Johnson's 1st Division,
John M. Palmer's
XIV Corps,
George Henry Thomas'
Army of the Cumberland. According to Fetterman's report in the
Official Records, the 2nd Battalion skirmished at
Buzzard Roost Gap and
Resaca. In fighting near
Pickett's Mill on May 31, the battalion sustained a loss of 1 officer and 33 men wounded. The battalion skirmished at the
Battle of Kennesaw Mountain and took part in an attack that overran a line of Confederate rifle pits on July 4. After July 5, the companies of the 2nd Battalion were merged with the 1st Battalion of the 18th US Infantry. Fetterman subsequently was assigned as Assistant Adjutant General of the 2nd Brigade and reported on a successful attack at the
Battle of Jonesborough on September 1. In this action, the 18th US Infantry suffered losses of 43 killed or wounded and 8 missing out of the 269 officers and men it took into battle. After the war, he chose to remain in the
Regular Army and was assigned as a
captain in the Second Battalion of the 18th Infantry Regiment. In November 1866, the regiment was stationed at
Fort Phil Kearny, tasked with protecting immigrants traveling to the gold fields of
Montana Territory along the
Bozeman Trail. Fetterman allegedly boasted that with 80 soldiers, he could "ride through the whole Sioux nation." On December 21, 1866, a large band of
Cheyenne and
Sioux – which included
Crazy Horse – under the leadership of
Red Cloud attacked a wood train near the fort. Despite his unfamiliarity with frontier conditions and the methods of Indian fighting, Fetterman took command of a composite reaction force consisting of the former battalion quartermaster, Captain Frederick Brown, 2nd Lt. George Grummond, 49 enlisted troops of the 18th Infantry, 27 men of the
2nd Cavalry, and 2 civilian scouts, totaling 80 men. Ignoring his orders not to venture beyond Lodge Trail Ridge (out of sight and support distance from the fort), Fetterman pursued a small band of Sioux and was lured into an ambush. He found himself facing approximately 2,000 Indians. Within 20 minutes, Fetterman and his command had been wiped out. The
Fetterman Fight, as the encounter became known, was second in notoriety only to
Custer's disastrous defeat in 1876. It led to the dismissal of Fetterman's commanding officer,
Henry B. Carrington, who was initially blamed for the disaster, but was eventually exonerated. Fetterman's grave is in the National Cemetery at the
Little Bighorn Battlefield National Monument. He had never married and left no heirs. ==Legacy==