In 1861, Hancock transferred from frontier duty back to the East with an appointment to brigadier general. In 1862, he led his brigade through the Peninsula campaign, and the subsequent Maryland campaign. During the Battle of Antietam, he succeeded in command of a division, and consequently received a promotion to major general in November 1862. He served in the battles of Fredericksburg, and Chancellorsville. At the Battle of Gettysburg, he was wounded, however, he remained on the front throughout the 1864 campaign. In November 1864, complications with his wound force him to leave his field command, so he assumed departmental command in February 1865, a position which he held until the end of the war.