in May 1862 in the newly created V Corps. His men, who often referred to themselves as "Sykes' Regulars", distinguished themselves defending their position at Gaines' Mill during the Seven Days Battles, before the Union line broke elsewhere. Sykes was notably the only division commander in the Army of the Potomac not rewarded with a promotion to major general after the Seven Days Battles. He continued leading his division at Second Bull Run, Antietam, and Fredericksburg, although it was not heavily engaged in the latter two battles. At Chancellorsville, his regulars led the advance into the Confederate rear at the start of the battle. Sykes' division engaged Maj. Gen. Lafayette McLaws' division on the Orange Turnpike. Sykes' division was forced to retreat after being attacked on the right flank by Maj. Gen. Robert E. Rodes' division, then the army commander, Maj. Gen. Joseph Hooker, nervously recalled his advance to a defensive position; and Sykes' men were not engaged for the remainder of the campaign. Sykes finally received a promotion to major general of volunteers on November 29, 1862. When corps commander Maj. Gen. George G. Meade was promoted to lead the Army of the Potomac on June 28, 1863, Sykes assumed command of the V Corps. At the Battle of Gettysburg, Sykes' corps fought in support of the beleaguered III Corps on the Union left flank. In his 1st Division (Brig. Gen. James Barnes), the fabled defense of Little Round Top was led by brigade commander Col. Strong Vincent and the 20th Maine Infantry under Col. Joshua Lawrence Chamberlain. His 3rd Division, the Pennsylvania Reserves, led by Brig. Gen. Samuel W. Crawford, attacked from Little Round Top, drove the Confederates across the "Valley of Death" and ended the deadly fighting in the Wheatfield. On October 16, 1863, Sykes was promoted to lieutenant colonel in the regular army. Sykes and his corps served in the Battle of Mine Run and in the Battle of Bristoe Station in the fall of 1863. In March 1864, upon recommendation from the V Corps medical director due to severe sciatica, Sykes was relieved of command of the V Corps and sent to uneventful duty in the Department of Kansas. During Price's Raid in 1864, he was replaced with James G. Blunt. Postbellum career After the war, Sykes was mustered out of the volunteer service and returned to serve in the regular army in 1866. As