Gibbon was was raised in North Carolina. He graduated from West Point in 1847, ranked 20 out of 38 in his class. He was commissioned a 2nd lieutenant in the 3rd U.S. Artillery. He served in the Mexican War, the Seminole War, and as an artillery instructor at West Point, where he wrote "The Artillerist's Manual" in 1859. The manual was a highly scientific treatise on gunnery and
was used by both sides in the Civil War.
When the Civil War started, Gibbon was serving as a captain of the 4th U.S. Artillery and became Chief of Artillery to Major Gen. Irvin McDowell. In 1862, he was appointed Brigadier General of volunteers and commanded the brigade of westerners known as the "Black Hat Brigade" , due to their distinctive black Hardee caps that he selected for them. He led the brigade into action against Confederate Lieutenant Gen. Thomas J. "Stonewall" Jackson's famous Stonewall Brigade at Brawner's Farm in the 2nd Bull Run. He was still in command of the brigade during their strong uphill charge at South Mountain, where Major Gen. Joseph Hooker exclaimed that the men "fought like iron". From then on the brigade was known as the "Iron Brigade". Gibbon led the brigade for the last time at Antietam, where he was forced to take time away from brigade command to personally man an artillery piece in the bloody fighting at the Cornfield.
Gibbon was promoted to command the 2nd Division, I Corps at Fredericksburg, where he was wounded. He recovered in time for Chancellorsville, but his division was in reserve and saw little action. At Gettysburg, he commanded the 2nd Division, II Corps and temporarily commanded the corps on July 1 and July 2, 1863, while Brigadier Gen. Winfield S. Hancock was elevated to command larger units. At the end of the council of war on the night of July 2, army commander Major Gen. George G. Meade took him aside and predicted, "If Lee attacks tomorrow, it will be on your front." And his division did bear the brunt of fighting during the defense against Pickett's Charge on July 3, when he was again wounded. While recovering from his wounds, he commanded a draft depot in Cleveland, Ohio.
Gibbon was back in command of the 2nd Division at the battles of the Wilderness, Spotsylvania Court House, and Cold Harbor. During the siege of Petersburg, he became disheartened when his troops refused to fight at Ream's Station. He went on sick leave, but his service being too valuable, he returned to command the newly created XXIV Corps in the Army of the James. His troops helped achieve the decisive breakthrough at Petersburg, capturing Fort Gregg, part of the Confederate defenses. He led his troops during the Appomattox Campaign and blocked the Confederate escape route at Appotamox Court House. He was 1 of 3 commissioners for the Confederate surrender.
After the war, Gibbon stayed in the army. He reverted to the Regular Army rank of Colonel and was in command of the infantry at Fort Ellis, Montana Territory, during the campaign against the Sioux in 1876. Gibbon, Major Gen. George Crook, and Lieutenant Col. George A. Custer were to make a coordinated campaign against the Sioux and Cheyenne, but Crook was driven back at the Battle of the Rosebud, and Gibbon was not close by when Custer attacked a very large village on the banks of the Little Bighorn River. The Battle of the Little Bighorn resulted in the deaths of Custer and some 261 of his men. Gibbon's approach on June 26 probably saved the lives of the several hundred men who were still under siege. Gibbon arrived the next day, and helped to bury the dead and evacuate the wounded.
Gibbon was still in command in Montana the following year when he intercepted a telegraph from Major Gen. Oliver O. Howard to cut off the Nez Percé, who were camped along the Big Hole River in western Montana. At the Battle of the Big Hole, his forces inflicted heavy losses, but became pinned down under Indian sniper fire. He held off the warriors until Howard's forces arrived late on the second day of battle and drove them off. He was promoted to Brigadier General in the regular army in 1885 and took command of the Army of the Pacific Northwest. He placed Seattle, Washington, under martial law during the anti-Chinese riots of 1886.
Gibbon is buried in Arlington National Cemetery. He is the author of "Personal Recollections of the Civil War", published posthumously in 1928, and "Adventures on the Western Frontier ."