Born September 13, 1813 at Cornwall Hollow, CT, John Sedgwick was the second child of Benjamin and Olive Sedgwick. Educated at the prestigious Sharon Academy, Sedgwick worked as a teacher for two years before electing to pursue a military career. Appointed to West Point in 1833, his classmates included Braxton Bragg, John C. Pemberton, Jubal A. Early, and Joseph Hooker. Graduating 24th in his class, Sedgwick received a commission as a second lieutenant and was assigned to the 2nd US Artillery. In this role he took part in the Second Seminole War in Florida and later aided in the relocation of the Cherokee Nation from Georgia. Promoted to first lieutenant in 1839, he was ordered to Texas seven years later following the outbreak of the Mexican-American War.
Initially serving with Major General Zachary Taylor, Sedgwick later received orders to join Major General Winfield Scott's army for its campaign against Mexico City. Coming ashore in March 1847, Sedgwick took part in the Siege of Veracruz and Battle of Cerro Gordo. As the army neared the Mexican capital, he was brevetted to captain for his performance at the Battle of Churubusco on August 20. Following the Battle of Molino del Rey on September 8, Sedgwick advanced with American forces at the Battle of Chapultepec four days later. Distinguishing himself during the fighting, he received a brevet promotion to major for his gallantry. With the end of the war, Sedgwick returned to peacetime duties. Though promoted to captain with the 2nd Artillery in 1849, he elected to transfer to the cavalry in 1855.
Appointed a major in the US 1st Cavalry on March 8, 1855, Sedgwick saw service during the Bleeding Kansas crisis as well as took part in the Utah War of 1857-1858. Continuing operations against the Native Americans on the frontier, he received orders in 1860 to establish a new fort on the Platte River. Moving up the river, the project was badly hampered when expected supplies failed to arrive. Overcoming this adversity, Sedgwick managed to construct the post before winter descended on the region. The following spring, orders arrived directing him to report to Washington, DC to become lieutenant colonel of the US 2nd Cavalry. Assuming this position in March, Sedgwick was in the post when the Civil War began the following month. As the US Army began to rapidly expand, Sedgwick moved through roles with various cavalry regiments before being appointed a brigadier general of volunteers on August 31, 1861.
Army of the Potomac
Placed in command of the 2nd Brigade of Major General Samuel P. Heintzelman's division, Sedgwick served in the newly formed Army of the Potomac. In the spring of 1862, Major General George B. McClellan began moving the army down the Chesapeake Bay for an offensive up the Peninsula. Assigned to lead a division in Brigadier General Edwin V. Sumner's II Corps, Sedgwick took part in the Siege of Yorktown in April before leading his men into combat at the Battle of Seven Pines at the end of May. With McClellan's campaign stalling in late June, the new Confederate commander, General Robert E. Lee commenced the Seven Days Battles with the goal of driving Union forces away from Richmond. Achieving success in the opening engagements, Lee attacked at Glendale on June 30. Among the Union forces that met the Confederate assault was Sedgwick's division. Helping to hold the line, Sedgwick received wounds in the arm and leg during the fight.
Promoted to major general on July 4, Sedgwick's division was not present at the Second Battle of Manassas in late August. On September 17, II Corps took part in the Battle of Antietam. In the course of the fighting, Sumner recklessly ordered Sedgwick's division to mount an assault into the West Woods without conducting proper reconnaissance. Moving forward, it soon came under intense Confederate fire before Major General Thomas "Stonewall" Jackson's men attacked the division from three sides. Shattered, Sedgwick's men were forced into a disorganized retreat while he was wounded in the wrist, shoulder, and leg. The severity of Sedgwick's injuries kept from active duty until late December when he took command of II Corps.
Sedgwick's time with II Corps proved brief as he was reassigned to lead IX Corps the following month. With the ascent of his classmate Hooker to the leadership of the Army of the Potomac, Sedgwick was again moved and took command of VI Corps on February 4, 1863. In early May, Hooker secretly took the bulk of the army west of Fredericksburg with the goal of attacking Lee's rear. Left at Fredericksburg with 30,000 men, Sedgwick was tasked with holding Lee in place and mounting a diversionary attack. As Hooker opened the Battle of Chancellorsville to the west, Sedgwick received orders to attack the Confederate lines west of Fredericksburg late on May 2. Hesitating due to a belief that he was outnumbered, Sedgwick did not advance until the next day. Attacking on May 3, he carried the enemy position on Marye's Heights and advanced to Salem Church before being halted.
The next the day, having effectively defeated Hooker, Lee turned his attention to Sedgwick who had failed to leave a force to defend Fredericksburg. Striking, Lee quickly cut the Union general off from the town and compelled him to form a tight defensive perimeter near Bank's Ford. Fighting a determined defensive battle, Sedgwick turned back Confederate assaults late in the afternoon. That night, due to a miscommunication with Hooker, he withdrew across the Rappahannock River. Though a defeat, Sedgwick was credited by his men for taking Marye's Heights which had held out against determined Union attacks during the Battle of Fredericksburg the previous December. With the end of fighting, Lee began moving north with the intention of invading Pennsylvania.
As the army marched north in pursuit, Hooker was relieved of command and replaced with Major General George G. Meade. As the Battle of Gettysburg opened on July 1, VI Corps was among the farthest Union formations from the town. Pushing hard through the day on July 1 and 2, Sedgwick's lead elements began to reach the fight late on the second day. While some VI Corps units aided in holding the line around the Wheatfield, the bulk of were placed in reserve. Following the Union victory, Sedgwick took part in the pursuit of Lee's defeated army. That fall, his troops won a stunning victory on November 7 at the Second Battle of Rappahannock Station. Part of Meade's Bristoe Campaign, the battle saw VI Corps take over 1,600 prisoners. Later that month, Sedgwick's men took part in the abortive Mine Run Campaign which saw Meade attempt to turn Lee's right flank along the Rapidan River.
During the winter and spring of 1864, the Army of the Potomac underwent a reorganization as some corps were condensed and others were added to the army. Having come east, Lieutenant General Ulysses S. Grant worked with Meade to determine the most effective leader for each corps. One of two corps commanders retained from the previous year, the other being II Corps' Major General Winfield S. Hancock, Sedgwick began preparations for Grant's Overland Campaign. Advancing with the army on May 4, VI Corps crossed the Rapidan and became engaged in the Battle of the Wilderness the next day. Fighting on the Union right, Sedgwick's men endured a sharp flank attack by Lieutenant General Richard Ewell's corps on May 6 but were able to hold their ground.
The next day, Grant elected to disengage and continue pressing south towards Spotsylvania Court House. Pulling out of line, VI Corps marched east then south via Chancellorsville before arriving near Laurel Hill late on May 8. There Sedgwick's men mounted an attack on Confederate troops in conjunction with Major General Gouverneur K. Warren's V Corps. These efforts proved unsuccessful and both sides began fortifying their positions. The next morning, Sedgwick rode out to supervise the placing of artillery batteries. Seeing his men flinch due to fire from Confederate sharpshooters, he exclaimed: “They couldn't hit an elephant at this distance." Shortly after making the statement, in a twist of historical irony, Sedgwick was killed by a shot to the head. One of the most beloved and steady commanders in the army, his death proved a blow to his men who referred to him as "Uncle John". Receiving the news, Grant repeatedly asked: “Is he really dead?” While command of VI Corps passed to Major General Horatio Wright, Sedgwick's body was returned to Connecticut where he was buried in Cornwall Hollow. Sedgwick was the highest ranking Union casualty of the war.