Joseph King Fenno Mansfield (December 22, 1803 – September 18, 1862) was a career United States Army officer, civil engineer, and a Union general in the American Civil War, mortally wounded at the Battle of Antietam. Early life Mansfield was born to Henry and Mary Fenno Mansfield in New Haven, Connecticut, a cousin of Joseph G. Totten. He entered the United States Military Academy when he was fourteen and graduated second in a class of forty in 1822. He then became a resident of Middletown, Connecticut before and during his military career. He was commissioned a second lieutenant in the U.S. Army Corps of Engineers. Advancement came slowly in the peacetime Army and he was promoted to first lieutenant in 1832, captain in 1838. In the Mexican–American War, he received a brevet promotion to major for the action at Fort Brown, Texas, on May 9, 1846. He was wounded in the leg at the Battle of Monterrey, and he received a brevet promotion to lieutenant colonel for his actions there. He was appointed a brevet colonel for the Battle of Buena Vista in 1847. After the war he was promoted to colonel and Inspector General of the U.S. Army on May 28, 1853. Civil War At the start of the Civil War, Mansfield commanded the Department of Washington (April 27 - August 17, 1861), and was promoted to brigadier general on May 6, 1861. General-in-chief Winfield Scott recommended Mansfield for command of the volunteer army being raised in Washington D.C. that spring, but the command went to Irvin McDowell instead. Mansfield was not considered the best choice due to his relatively advanced age and skepticism of volunteer troops and the administration's push for a quick drive on Richmond that would end the war in a few months, and he also lacked a political sponsor in Washington. After the Union rout at Bull Run, George McClellan was put in command of the war effort in the Eastern Theater and Mansfield's hopes of army command were again dashed. McClellan also did not offer him a command in the newly-created Army of the Potomac. Mansfield was stationed at Hatteras Inlet, North Carolina, in October, following the battle fought there by Benjamin Butler in August. He was a brigade commander in the Department of Virginia from March to June 1862. His only combat activity during this period was the firing of coastal batteries from