From the Peninsula to Maryland: Mansfield's role in the summer of 1862
- Major General commanding XII Corps Union Army of the Potomac
- Place of Birth:
- New Haven, CT
- Date of Birth
- December 22, 1803
- Place of Death:
- Sharpsburg, MD
- Date of Death
- September 18, 1862
- Place of Burial:
- Middletown, CT
- Cemetery Name
- Indian Hill Cemetery
At age 59 Joseph King Mansfield was one of the oldest field officers in the Army of the Potomac. Until the Maryland Campaign Mansfield had commanded the Suffolk Division of the VII Corps of the Department of Virginia, but when Lee invaded the North in September Mansfield was given command of the XII Corps of the Army of the Potomac.
He took command of the Corps on September 15, only two days prior to the Battle of Antietam. He brought 40 years of army experience with him, but had seen no recent combat. His officers considered him nervous and fussy, but his men, many of whom were new recruits, enjoyed his shows of blustery enthusiasm and fatherly assurance. Though white-haired and white-bearded, he possessed a vigorous manner that belied his age.
On the morning of September 17, when Joseph Hooker's I Corps smashed into the Confederate left flank, Mansfield's corps came up to support the attack.
As his lead brigade moved through an open field east of the Miller farmstead, they came under Confederate artillery fire, which took a fearsome toll on the unseasoned soldiers. In an effort to reduce the casualties being taken from the artillery the brigade was ordered to shift from column of march into open battle line. Mansfield quickly countermanded these orders, insisting the men stay in column, arguing that the officers could maintain better control and move more rapidly.
In order to insure the proper movement of his men Mansfield personally led the troops on his left flank, from the Samuel Crawford's brigade, into the East Woods.
Returning to the rear to bring up more troops, he saw the 10th Maine Infantry regiment firing into the woods. Mansfield, assuming that men from I Corps were in the woods, rode down the regimental line crying out, "You are firing on our own men!" Even as the infantrymen informed Mansfield that they were firing at Confederates and were themselves receiving heavy fire from the woods, that fire intensified and Mansfield was hit squarely in the chest.
Tottering in his saddle, Mansfield pushed his bleeding horse (which had also been hit) away from the men, and rode north until he came upon the 125th Pennsylvania. Noticing that the General seemed ill Captain Gardner called for some men to help him dismount.
Forming a chair of sorts with their muskets, five men picked up Mansfield and carried him to a lone tree in the rear of their line, where they left him to await the arrival of a surgeon.
Regimental Surgeon Dr. Patrick Henry Flood described what he found when he arrived: "I found the clothing around his chest saturated with blood, and upon opening them, found he was wounded in the right breast, the ball penetrating about two inches from the nipple, and passing out the back, near the edge of the shoulder blade."
Mansfield was taken to a field hospital at the George Line farm in Sharpsburg, where he died the next morning.
He is one of six generals to be killed or mortally wounded at the Battle of Antietam.