John Sedgwick was born at Cornwall Hollow, Connecticut on September 13, 1813. He was the son of Benjamin and Olive (Collins) Sedgwick. He was named after his grandfather, John Sedgwick, an American Revolutionary War general who served under George Washington and survived the grim winter of 1777 at Valley Forge, Pennsylvania.
After receiving his primary instruction at the local common school, Sedgwick attended nearby Sharon Academy and, afterward, Cheshire Academy. As a teenager, Sedgwick taught school for two years during the winter and worked on the family farm during the summer.
U.S. Military Academy Cadet
In 1833, Jabez Huntington, United States Senator from Connecticut, helped Sedgwick receive an appointment to the United States Military Academy. Sedgwick entered the Academy on July 1, 1833. Among his classmates were future Confederate generals Braxton Bragg, John C. Pemberton, Jubal Early, and William H. T. Walker and future Union general Joseph Hooker. During his four years at West Point, Sedgwick proved to be an average student, graduating twenty-fourth out of his class of fifty cadets on July 1, 1837.
U.S. Army Officer
Following his graduation, army officials commissioned Sedgwick as a second lieutenant with the 2nd U.S. Artillery and sent him to Florida for two years, where he took part in the Second Seminole War (1835-1842). Between 1838 and 1846, Sedgwick performed recruiting and garrison duty at numerous locations, mostly in the eastern United States. On April 19, 1839, the army promoted him to first lieutenant.
Like many future Civil War general officers, Sedgwick took part in the Mexican-American War (April 25, 1846-February 2, 1848). He first served with General Zachary Taylor’s army in northern Mexico. He later served with General Winfield Scott’s invasion force at the Siege of Veracruz (March 9-29, 1847), the Battle of Cerro Gordo (April 17-18, 1847), the Battle of Churubusco (August 20, 1847), the Battle of Molino del Rey (September 8, 1847), the Battle of Chapultepec (September 12‑13, 1847), and the assault and capture of the City of Mexico (September 13‑14, 1847). During the war, Sedgwick received a brevet promotion to captain for gallant and meritorious conduct in the Battles of Contreras and Churubusco, effective August 20, 1847, and a brevet promotion to major for gallant and meritorious conduct in the Battle of Chapultepec, effective September 13, 1847.
Service in the West
Upon returning from the Mexican-American War in 1848, Sedgwick served another seven years on garrison duty at various posts in the eastern United States. During that period, he received a promotion to captain on January 26, 1849.
On March 8, 1855, the army promoted Sedgwick to major with the 1st Cavalry and transferred him west. While serving in the West, Sedgwick helped quell violence during the Border Wars in Kansas, campaigned against the Cheyenne, Kiowa, and Comanche Indians, and took part in the Utah Expedition against Mormon settlers.
Union Army Officer
As the sectional dissension intensified following the election of President Abraham Lincoln, army officials promoted Sedgwick to lieutenant colonel on March 16, 1861, and sent to Washington, DC. On April 25, he received another promotion to the full rank of colonel and officials placed him in charge of the 1st Cavalry after its commander, Robert E. Lee, resigned.
After the Civil War began, Sedgwick helped prepare defenses for the nation’s capital from June to August 1861. On August 3, army officials transferred Sedgwick to the 4th Cavalry. He briefly held the position of Acting Inspector-General of the Department of Washington until August 12, when officials placed him in command of the 2nd brigade of Major General Samuel P. Heintzelman’s division in the Army of the Potomac. On December 5, 1861, the U.S. War Department issued General Order No. 106, commissioning Sedgwick as a brigadier general in the volunteer army to date from August 31, 1861.
Army of the Potomac Divisional Commander
Following the Union disaster at the First Battle of Bull Run (July 21, 1861), President Lincoln turned to Major General George B. McClellan to reorganize federal forces in the East. By the spring of 1862, President Lincoln drafted his own reorganization plan for the Army of the Potomac. On March 8, he issued War Order No. 2, merging the army’s divisions into five corps. Lincoln named Major General Irvin McDowell, Brigadier General Edwin V. Sumner, Brigadier General S. P. Heintzelman, Brigadier General Erasmus D. Keyes, and Major General Nathaniel P. Banks to command the five corps, respectively. On March 13, 1862, a disgruntled McClellan issued General Order No. 101 (Army of the Potomac), confirming the President’s selections. McClellan’s order also appointed division commanders for each of the corps. McClellan assigned Sedgwick to command the 2nd Division of Sumner’s 2nd Corps.
During McClellan’s ill-fated Peninsula Campaign in the spring of 1862, Sedgwick commanded his division at several major engagements, including the Siege of Yorktown (April 5-May 4, 1862), the Battle of Fair Oaks (May 31-June 1, 1862) the Battle of Savage’s Station (June 29, 1862), and the Battle of Glendale (June 30, 1862), where he received wounds to arm and leg. On November 1, 1862, the United States War Department issued General Order No. 181, announcing Sedwick’s commission as a major general in the volunteer army, effective July 4, 1862.
Northern Virginia Campaign
When McClellan withdrew from the Virginia Peninsula during the summer of 1862 following the failed Peninsula Campaign, officials sent Sumner’s Corps to northern Virginia to support Major General John Pope’s Army of Virginia. The 2nd Corps, including Sedgwick’s division, arrived near Manassas but not in time to take part in the Union defeat at the Second Battle of Bull Run (August 28-30, 1862).
Following Pope’s defeat, Robert E. Lee took the war onto Northern soil, marching the Army of Northern Virginia into Maryland on September 4, 1862. An anxious President Lincoln reluctantly turned to Major General George B. McClellan to reinvigorate the federal forces and to stop Lee’s advance. On September 2, 1862, Lincoln placed McClellan in command of “the fortifications of Washington, and all the troops for the defense of the capital.” McClellan merged the Army of Virginia with his Army of the Potomac and moved to halt Lee’s incursion.
Wounded at the Battle of Antietam
McClellan held Sumner’s corps in reserve during the Union victory at the Battle of South Mountain (September 14, 1862). Three days later, on the single bloodiest day of fighting in American military history (September 17, 1862), Sumner ordered an ill-conceived and uncoordinated attack by Sedgwick’s division that contributed to the high casualty total at the Battle of Antietam (September 16-18, 1862). Sedgwick received three bullet wounds during the engagement, forcing him to go on leave from September 18 to December 22, 1862, as he recuperated. Sedgwick’s injuries caused him to miss the Battle of Fredericksburg (December 11-15, 1862).
When Sedgwick returned to active duty in December 1862, officials elevated him to a corps commander. He commanded the 2nd Corps for one month and of the 9th Corps for three weeks. On January 26, 1863, the War Department issued General Orders, No. 20, announcing that President Lincoln had replaced Major General Ambrose E. Burnside with Major General Joseph Hooker as commander of the Army of the Potomac. On February 5, 1863, Hooker issued General Orders, No.6 (Army of the Potomac), announcing the appointment of seven corps commanders, including Sedgwick as commander of the 6th Corps, the unit with which his career is most identified.
In early May 1863, Hooker began an offensive against Confederate General Robert E. Lee’s Army of Northern Virginia near Chancellorsville, Virginia. Hooker ordered Sedgwick to launch a diversionary attack against Lee at Fredericksburg on May 2, while Hooker tried to march the bulk of his army around Lee’s forces and attack from the rear.
Sedgwick’s assault during the Battle of Chancellorsville (April 30-May 6, 1863) came one day late, enabling Lee to focus his attention on Hooker. Sedgwick’s men belatedly drove Confederate General Jubal Early’s defenders off of Marye’s Heights above Fredericksburg on the morning of May 3, at the same time that Lee was repulsing Hooker’s assault. With Hooker disposed of, Lee turned his attention to Sedgwick on the next day, pushing the 6th Corps back across the Rappahannock River.
At the Battle of Gettysburg (July 1-3, 1863), Sedgwick’s Corps was far from the initial fighting. After a forced march of twenty hours, his men reached the fighting on July 2. Because of exhaustion, most of the 6th Corps stood in reserve during the decisive Union victory.
On March 10, 1864, President Lincoln appointed Ulysses S. Grant as General-in-Chief of the Armies of the United States. With the help of Major General George G. Meade, Grant immediately set about reorganizing the Army of the Potomac. Under the new structure, Sedgwick maintained his position as commander of the 6th Corps.
When Grant launched his Overland Campaign (May 5-June 24, 1864), Sedgwick’s corps was heavily engaged at the initial conflict, the Battle of the Wilderness (May 5-7, 1864). Although the Rebels won the battle, Grant did not retreat. Instead, on May 7, he ordered Meade to move his army deeper into Confederate territory, southeast towards Spotsylvania Court House.
Death at Spotsylvania
Robert E. Lee realized the importance of not allowing Grant to get between him and Richmond. Thus, on May 8, the two armies raced to Spotsylvania. Unfortunately for the Federals, the Rebels reached the community first, enabling them to establish superior defensive positions.
On May 9, Rebel sharpshooters, armed with highly accurate Enfield and Whitworth rifles, fired on Sedgwick as he was overseeing the placement of an infantry line. As his soldiers began ducking bullets, Sedgwick admonished them, reportedly exclaiming:
What! What! Men, dodging this way for single bullets! What will you do when they open fire along the whole line? I am ashamed of you. They couldn’t hit an elephant at this distance.
After a brief exchange with one of his soldiers, just seconds or minutes later (depending upon the account) a bullet struck Sedgwick below the left eye, killing him almost instantly. The sharpshooter’s bullet made “Uncle John,” as his soldiers affectionately referred to him, the highest-ranking Union combat casualty of the Civil War.
Officials returned Sedgwick’s remains to his hometown of Cornwall Hollow, Connecticut, where they were buried at Cornwall Hollow Cemetery.