John Caldwell was still a young man of thirty at Gettysburg, and one of the rare division commanders with absolutely no acquaintance with military affairs before the Civil War. Neither did he have much battle experience leading a division prior to the Gettysburg Campaign; he had only recently been promoted to his present command when Maj. Gen. Winfield S. Hancock, the previous division commander, had been lifted to the head of the Second Corps on May 22, 1863.

The new division leader was a scholarly type. Born in Vermont, graduated from Amherst, Caldwell served as teacher and principal at the Washington Academy at East Machias, Maine, for five years preceding the onset of the War. For a man with no military background he evidently commanded considerable respect, for in November 1861 he was made colonel of the 11th Maine Regiment, which he led off to the Army of the Potomac's Peninsula Campaign in the spring of 1862. Here too he caught somebody's eye. In April 1862, just as the campaign was getting under way, he was made brigadier general, and in June he received command of the First Brigade, First Division, Second Corps (commanded at Gettysburg by Colonel Cross) after Brig. Gen. Oliver O. Howard, its previous commander, was wounded at Seven Pines.

Caldwell led his brigade with uneven success through the army's battles of the following months:

He was personally thanked for his "personal gallantry" in coming to the aid of Kearny's division in the crucial action at Glendale during the Seven Days' Battles.

At Antietam in September 1862 he directed the division briefly after division leader Maj. Gen. Israel Richardson was wounded while supervising his artillery. After the battle, however, it was whispered that Caldwell had hidden himself in the rear behind a haystack. There too, his handling of the brigade in the assault on the Bloody Lane was criticized as lax.

At Fredericksburg he was twice wounded. Preparing his men to charge the Stone Wall, he was struck in the left side, but did not leave the field. A few minutes later he was hit again, in the left shoulder, but yet remained to direct one of his regiments. Here again, however, there was a stain on Caldwell's record: one of his regiments broke and ran to the rear.

At Chancellorsville Caldwell performed well in difficult circumstances when, on May 3, the division was forced to face in opposite directions and cover the retreat of the army around the Chancellor House.

By the time of Gettysburg Caldwell was one of the most experienced brigade commanders in the army. Despite his volunteer's background, he evidently enjoyed the confidence of Hancock, who otherwise would have suggested someone else to command the First Division when he was promoted. The men under him spoke well of him, too. "Caldwell is an agreeable man and well liked," wrote one man of his brigade who served with him before Gettysburg. "There is none of the assumed dignity and importance so common among officers. . . . He is much more familiar with his officers than General Meagher [of the Irish Brigade] and is much better like by them than M[eagher] by his." However, when Hancock left the Second Corps to go personally to Gettysburg on July 1, Meade ordered that Brig. Gen. John Gibbon of the Second Division take command of the corps, in spite of the fact that Caldwell outranked him. This was probably a reflection of Caldwell's lack of training as a professional soldier, given Meade's strong preference for West Pointers.

Caldwell had been a good, not great, brigade commander. He knew the division well. But he had no military training, and at Gettysburg he was leading a division into battle for the first time, having just been installed in command a few weeks before.

At Gettysburg
Arriving early in the morning of the July 2 by way of the Taneytown Road, Caldwell's division was initially placed in the middle of on Cemetery Ridge as a reserve, in a formation that enabled it to move quickly. Around 5:00 that afternoon, when the call for help came from Dan Sickles's front, Caldwell had all four of his brigades moving within minutes. Approaching the Wheatfield from the north, he then delivered the only division-sized Federal assault in all three days at Gettysburg. The attack was handled expertly, just as the mobilization had been: within ten minutes, in unfamiliar terrain with nothing to guide them but the sound of the heaviest fighting, three of Caldwell's brigades were surging in unison against the enemy. The sudden attack threw three Confederate brigades back in disorder and gained ground beyond the original Union line. A short time later, however, McLaws's Rebel division rushed forward, and two fresh enemy brigades bore down on Caldwell's exposed right flank.

When his attack stalled, Caldwell continued to be active and alert, riding in person (essentially acting as his own staff) to ask for the support of nearby brigades when it became evident that no higher officer was overseeing or coordinating the Union effort in this critical part of the battlefield. While he was thus occupied, he couldn't see that McLaws's brigades had already started his division tumbling back from the Wheatfield. An aide finally got his attention and pointed to his men running away in confusion. Caldwell's division's remnants were sent flying pell-mell to the rear, and couldn't be rallied until after dark.

Caldwell was unjustly criticized by Maj. Gen. George Sykes, the Fifth Corps chief, who reported to Hancock that the division had "done badly." As a result, Caldwell lost Hancock's confidence--this was Hancock's old division, after all. He withheld praise from Caldwell after the battle, and ordered an investigation of the July 2 conduct by the First Division. The investigation vindicated Caldwell. Lieutenant Colonel C.H. Morgan of Hancock's staff, who himself had come upon Caldwell's division in full flight to the rear, wrote "[the investigation] showed that no troops on the field had done better."

Despite Caldwell's vindication, Hancock replaced him less than a year later, when in March 1864 the Army of the Potomac was consolidated from five corps to three.

For further reading:
Campbell, Eric. "Caldwell Clears the Wheatfield." Gettysburg Magazine 3, Jul 1990
Hartwig, D. Scott. "John C. Caldwell's Division in the Wheatfield." in Gary Gallagher, ed. The Second Day at Gettysburg, Kent, 1993

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