Forty Years of Service and a Single Moment of Glory - Joseph K. F. Mansfield (September 17, 1862)

 

For more than forty years Joseph Mansfield prepared for one test - high command in war. After a distinguished career marked by heroic service in the Mexican War, recognition and achievement as a military engineer and expert on fortifications, and Inspector General of the U.S. Army in the decade before the Civil War, his moment came on the morning of September 17, 1862 at the small Maryland village of Sharpsburg, where Antietam Creek runs east of the town.  Just two days into his job as commander of the XII Corps, Army of the Potomac, at 11:00 AM MG Mansfield led his men through the East Woods to renew the attack against the left of the Confederate line held by Stonewall Jackson’s Corps. The earlier attack by Hooker’s I Corps had nearly broken through, but melted away after terrific losses. By the end of the morning, the cornfield and woods near the Dunkard Church would be covered with the bodies of more than 8,000 dead and wounded Americans.

Joseph King Fenno Mansfield was born on December 22, 1803 in New Haven, a descendant of early English colonists and member of a prominent family of Middletown CT. The youngest of six children, his oldest brother had been commander of the company of Cincinnati Light Infantry that had surrendered with Hull’s whole army at Detroit in 1812, and was broken by the experience. When Joseph entered West Point in 1817 just five years later, he was the youngest in his class. Several of his relatives were prominent instructors at the Military Academy, and he performed exceptionally well, especially in natural philosophy, graduating in 1822 second in his class of 40, and winning a coveted commission in the prestigious Army Corps of Engineers. He spent the next quarter century as a military engineer, mostly designing coastal defenses like that at Fort Pulaski at the mouth of the Savannah River. At the outbreak of the Mexican War, he was appointed head engineer in General Zachary Taylor’s Army.

During the war he was brevetted three times, first, to major for building Fort Brown (opposite Matamoras on the Rio Grande) and then defending it during early May, 1846. Lt. George Gordon Meade, destined to command the Army of the Potomac at Gettysburg, wrote that Mansfield “had gained for himself great credit for the design and execution of the work and still more for his energy and bravery in its defense.” Second, he was brevetted to Lieutenant Colonel for “gallant and meritorious conduct” during the Battle of Monterey, during which he was seriously wounded (September 21-23, 1846); and third, to Colonel for “gallant services“ at the battle of Buena Vista on February 23, 1847. More than five years after the war, Mansfield was still a Captain, the result of reductions in the army and a glacially slow system of promotion that placed him third in line for promotion within the Corps of Engineers on a list that also included H.W. Halleck, G.B. McClellan, W.L. Rosecrans, P.G.T. Beauregard and Robert. E. Lee.

In May 1853, Mansfield was named Inspector General of the Army by Secretary of War Jefferson Davis, also a veteran of Taylor’s army. For a decade, Colonel Mansfield traveled the country inspecting Army facilities, especially in the western frontier. On May 18, 1861 he was named one of the new brigadier generals in the Regular Army created by Congress to fight the war and placed in command of the Department of Washington, including the defenses of the capital. His first major decision was to take and fortify Arlington Heights on his own authority. He next supervised the entire system of fortifications that successfully defended the capital throughout the war.

Mansfield was serving as military governor of Norfolk, VA when McClellan selected him to replace Banks as XII Corps Commander in the aftermath of Pope’s defeat at Second Manassas. Famed historian Bruce Catton describes the old man rallying his men for battle at Antietam as he “went galloping up to his troops, his hat in his hand, long white hair and beard streaming in the wind” and answering the shout of his soldiers, “That’s right boys, cheer – we’re gonna whip them today!” Later, dismounted from his wounded horse and scampering over a fence like a schoolboy, he was mortally wounded by a bullet to the stomach and succumbed early the next morning. His moment of glory had lasted just a few hours. Joseph K.F. Mansfield, 58, was oldest graduate of West Point serving as a general to die in battle.