Hancock was one of twin brothers, and named after the famous general Winfield Scott. He graduated from West Point in 1844, ranked 18 out of 25 in his class. He served in the infantry during the frontier duty, Mexican war, Seminole War, the Kansas border disputes, and the Utah expedition. His was a 2nd lieutenant in the 6th U.S. Infantry Regiment, with which he fought in
the Mexican War. He was brevetted to 1st lieutenant for gallant and meritorious service at Contreras and Churubusco, where he was wounded in the knee, in 1847.
He became the Chief Quartermaster, Southern District of California. Fearing that he would be left to sit in California-where he had been instrumental in frustrating the plans of local secessionists-while the war raged elsewhere, he was ordered East to the Quartermaster's Department. He had earned a brevet before the transfer. He was appointed a Brigadier General to date from September 23, 1861.
Hancock was given an infantry brigade to command in the Army of the Potomac. He earned his "Superb" designation in the Peninsula Campaign in 1862 by leading a critical attack on Fort Magruder at Williamsburg; sadly, Major Gen. George B. McClellan did not follow through on Hancock's initiative, and the Confederate forces were allowed to withdraw unmolested.
At Antietam, Hancock assumed division command in the II Corps following the death of Major Gen. Israel B. Richardson. He was promoted to major general of volunteers in November, 1862. He led his division in the disastrous attack on "Marye's Heights" at Fredericksburg was wounded in the abdomen. At Chancellorsville, his brigade covered Major Gen. Joseph Hooker's withdrawal and he was wounded again. His corps commander, Brigadier Gen. Darius Couch, transferred out of the Army of the Potomac in protest of actions Hooker took in the battle and he assumed command of II Corps, which he would lead for the rest of the war. He is considered by many to the best Union corps commander of the war.
Hancock's most famous service was as a new corps commander at Gettysburg. After Major Gen. John F. Reynolds was killed early on July 1, Major Gen. George G. Meade, the new commander of the Army of the Potomac, sent him to take command of the units on the field and assess the situation. He was in temporary command of the "left wing" of the army, consisting of the I, II, III, and XI Corps. He organized the Union defenses on Cemetery Hill as Confederate forces drove the I and XI Corps back through the town. He decided to stand and fight at the town of Gettysburg. He later received the thanks of the U.S. Congress for "for his gallant, meritorious and conspicuous share in that great and decisive victory". Meade arrived after midnight and overall command reverted to him.
On the second and third days of the battle, he directed the Union center until severely wounded in his thigh by a nail and by wood fragments, possibly from his saddle driven into his thigh by Confederate fire. His position bore the brunt of Pickett's Charge on July 3rd. Despite his pain, he refused evacuation to the rear until the battle was over. He had been an inspiration for his troops throughout the battle. After a recuperation leave of 6 months, he returned to active service.
Hancock suffered from the effects of his wound for the rest of the war. He did recruiting over the winter and returned in the spring to field command of the II Corps for Lieutenant Gen. Ulysses S. Grant's 1864 Overland Campaign, but he never regained full mobility and his former youthful energy. Nevertheless, he performed well at the Wilderness and commanded a critical breakthrough assault at the "Bloody Angle" at Spotsylvania Court House. His corps suffered enormous losses during a futile assault at Cold Harbor.
During the siege of Petersburg, Hancock's only significant reverse occurred. His corps moved south of the city, along the Weldon Railroad, tearing up track. On August 25, Major Gen. Henry Heth attacked and overran the Union position at Ream’s Station, shattering the II Corps, and capturing many prisoners. This humiliation was a principal reason for him giving up field command in November, but he also expressed his concern with Grant's casualty-intensive tactics. He performed more recruiting, commanded the Middle Department, and relieved Major Gen. Philip Sheridan in command of forces in the Shenandoah Valley.
After the war, Hancock commanded the the 5th Military District. During the Reconstruction, he drew much criticism from Grant and others for being lenient to the defeated Confederates. By 1866, he was a major general in the Regular Army, and eventually took command of the Department of the East.
Hancock was considered but passed over for the Democratic nomination for U.S. President in 1868. He was eventually chosen as the Democratic opponent to James Garfield in the U.S. election of 1880, but was narrowly defeated in his attempt.
Hancock died while still in command of the Department of the East. He was buried in Montgomery Cemetery in Norristown, Pennsylvania. He was considered one of the greatest Union generals serving in the East. He was known to army colleagues as "Hancock the Superb".
Brigadier General USV- September 23, 1861
Major General USV- November 29, 1862
Brigadier General USA- August 12, 1864
captain and assistant quartermaster (since November 7, 1855)
3rd Brigade, Smith's Division, Army of the Potomac (October 3, 1861 - March 13, 1862)
lst Brigade, 2nd Division, IV (VI after May 18) Corps, Army of the Potomac (March 13 - September 17, 1862)
lst Division, II Corps, Army of the Potomac (September 17, 1862 - January 24, 1863 and February 20 - May 22, 1863)
II Corps (May 22 - July 1, and July 2-3, 1863 and March 24 - June 18 and July 27 - November 26, 1864); major and quartermaster (November 30, 1863)
lst Veteran Volunteer Corps (November 27, 1864 - February 27, 1865)
Middle Military Division (February 27 - June 27, 1865)
Department of West Virginia (February 28 - March 1, March 7-20, and March 22 - June 27, 1865)