When he was just seventeen, Rhode Islander Frank Wheaton left his upper-crust surroundings at Brown University to take a job riding the range, surveying the U.S.-Mexico border. After five years experience on the frontier, he was appointed directly into the Regular Army as a first lieutenant of cavalry in 1855 without any formal military training. As a Regular, he fought Indians and went west with the Mormon Expedition. At the tender age of twenty-eight, he was already a hardened veteran trooper when the Civil War began.

Wheaton's family was shattered by the secession crisis. His father-in-law was Samuel Cooper, a New Yorker who was adjutant general of the U.S. Army. Cooper's wife was from a distinguished Virginia family, however, and Cooper sided with his wife's family, accepting an appointment to brigadier general in the Confederate Army on March 16, 1861. Cooper's daughter sided with husband Wheaton, who had just been promoted to captain in the U.S. cavalry on March 3. The guns boomed at Sumter on April 12.

Events then moved swiftly for Wheaton. He entered the volunteer service on July 10, 1861 as lieutenant colonel of the 2nd Rhode Island regiment, and eleven days later was fighting with his regiment in the battle of Bull Run. There the green Rhode Islanders were heavily engaged, and Col. John Slocum went down mortally wounded, pierced by three bullets. Wheaton took over command of the regiment in the middle of the battle, and was made the new colonel the same day, commended by brigade leader Col. Ambrose Burnside for his "admirable conduct."

Things calmed down while McClellan reorganized the army over the next several months, and in the summer of 1862, Wheaton's regiment took part in the Peninsula Campaign, but was never heavily engaged.

Again at Antietam Wheaton's division was too far in the rear to participate.

With this meager experience, Wheaton somehow wangled a promotion to brigadier general in November 1862. At the Battle of Fredericksburg in December, he still had not received his general's star, and remained with his regiment, who were deployed as skirmishers in the downriver crossing of the Rappahannock River and suffered few casualties. Two days after the fighting ended, however, Wheaton's promotion to general was approved, and he was transferred to command of the mostly Pennsylvanian Third Brigade, Third Division, Sixth Corps, which he joined immediately and led off the field.

His first experience in command of his brigade in combat had to wait until the following spring at the Battle of Chancellorsville. There, his brigade took part in the storming of Marye's Heights on May 3, and was thrown into the line as reinforcements during the Confederate counterattacks of May 4. For two days, Wheaton got plenty of experience handling multiple regiments under battle conditions--his brigade lost 485 men in hard fighting.

Approaching Gettysburg, then, Frank Wheaton, just thirty years of age, was the veteran of one battle as a brigade commander. But on the night of July 1-2, a few hours before he arrived with his brigade on the field, his immediate superior, division commander Maj. Gen. John Newton, was assigned to command the First Corps after the death of John Reynolds. That left Wheaton to command Newton's division, a job for which he was entirely unprepared.

At Gettysburg
First in Sedgwick's Sixth Corps column as it entered the battlefield at 5:00 on July 2 by the Baltmore Pike, Wheaton was immediately sent with his first two brigades to reinforce the embattled Fifth Corps units around Little Round Top. The lead brigade, Nevin's, arrived in time to participate in the Union charge just north of the hill which ended the fighting for the day.

On July 3, Wheaton issued the orders which shifted his three brigades between their assignments in the line, but never commanded any troops once they reached the front. None of his brigades were engaged.

Wheaton himself wrote no report of the battle.

Within a few hours after the battle he had been replaced by a new division commander and Wheaton returned to his brigade. He inherited command of the division permanently more than a year later--in September 1864--and held it until the end of the war.

Excerpted from "The Generals of Gettysburg: The Leaders of America's Greatest Battle" by Larry Tagg