Born in Dover, Delaware, George Sykes graduated from West Point in the class of 1842, the class that was to contribute no less than twelve Corps and Army commanders to the Civil War. Breveted to 2nd Lieutenant, 3rd Infantry, July 1, 1842, he served in the Florida War, 1842, followed by duty in garrison at Ft. Stansbury, FL, 1842-1843 and Jefferson Barracks, MO, 1843-1844. He was promoted to 2nd Lieutenant, 3rd Infantry, December 31, 1843 and assigned Frontier Duty at Ft. Jesup (Camp Wilkins), LA, 1844-1845 and duty in the Military Occupation of Texas under General Taylor, 1845-1846. Sykes was in the Mexican War, engaged in the Battle of Monterey, September 21-23, 1846. He was promoted to 1st Lieutenant, 3rd Infantry, September 21, 1846.  He was next in the Siege of Vera Cruz, March 9-29, 1847; and the Battle of Cerro Gordo, April 17-18, 1847, receiving a brevet to Captain, April 18, 1847, for gallant and meritorious conduct in the Battle of Cerro Gordo. He was engaged in the Battle of Contreras, August 19-20, 1847; Battle of Churubusco, August 20, 1847; Operations before and Capture of Mexico City, September 12-14, 1847; and as Commissary of Bvt. Major- General Twiggs' Division, 1847-1848.

After garrison at Jefferson Barracks, MO, 1848, Sykes was on Frontier Duty at: Santa Fe, NM, 1849; Navajo Nation, 1849-1850; and Santa Fe, NM, 1850. He was on Recruiting Duty, 1850-1852. He returned to Frontier Duty at: Ft. Union, NM, 1852-1854; Scouting against the Apache Indians, 1854, being engaged in Skirmishes, March 4, April 9 and June 30, 1854; Ft. Union, NM, 1854-1855; Ft. Massachusetts, CO, 1855; Ft. Union, NM, 1855 and Ft. Fillmore, NM, 1855-1857. He was promoted to Captain, 3rd Infantry, September 30, 1857. Sykes continued on Frontier Duty on the Gila Expedition, 1857, and at Ft. Fillmore, NM, 1857. He was on Detached Service at Baltimore, 1858; on Frontier Duty at Los Lunas, NM, 1858-1859; on the Navajo Expedition, 1859; at Ft. Defiance, NM, 1859; Las Lunas, NM, 1859- 1860; on the March to Texas, 1860; and Ft. Clark, TX, 1860-1861.



He was promoted to Major, 14th Infantry, May 14, 1861. He was engaged in the Manassas Campaign of July, 1861, being engaged in the Battle of Bull Run, July 21, 1861; in Washington, D. C., commanding the Regular Infantry, August, 1861-March, 1862. He was commissioned Brigadier-General, U. S. Volunteers, September 28, 1861. He was next in the Virginia Peninsular Campaign (Army of the Potomac), March-August, 1862, being engaged in the Siege of Yorktown, April 5-May 4, 1862; and Battle of Gaines's Mill, June 27, 1862. He was breveted to Colonel, June 27, 1862, for gallant and meritorious services in the Battle of Gaines's Mill, VA. Sykes was engaged in the Battle of Malvern Hill, July 1, 1862; and thereafter in the Northern Virginia Campaign, August-September, 1862, being engaged on the March from Fredericksburg to Bull Run, August, 1862; and the Battle of Manassas, August 29-30, 1862. In the Maryland Campaign (Army of the Potomac), September-November, 1862, he was engaged in the Battle of Antietam, September 17, 1862; Skirmish of Shepherdstown, VA, September 19, 1862; and March to Falmouth, VA, October-November, 1862, participating in the Skirmish of Snicker's Gap, VA, November 3, 1862.

Sykes was promoted to Major-General, U. S. Volunteers, November 29, 1862. In the Rappahannock Campaign (Army of the Potomac), December, 1862-June, 1863, he was engaged in the Battle of Fredericksburg, December 12-13, 1863; and Battle of Chancellorsville, May 2-4, 1863. At Chancellorsville, he was not involved in the rout of the Federal right and his casualties were less than 300 men. In the Pennsylvania Campaign, succeeding George C. Meade in command of V Corps (Army of the Potomac) after Meade was named commander of the Army of the Potomac, June-July, 1863,in the Battle of Gettysburg, July 1-3, 1863, Sykes played a crucial part in support of Sickles' III Corps position and the left of the Union line; and was thereafter in the Pursuit of the Enemy to Warrenton, VA, July, 1863. In the Rapidan Campaign, commanding V Corps, (Army of the Potomac), October-December, 1863, he was engaged on the Rappahannock, Rapidan, and in the movement on Centreville, October, 1863. He was promoted to Lieutenant Colonel, 5th Infantry, October 16, 1863. He was next engaged in the Combat on Rappahannock Station, November 7, 1863 and Actions on the Rapidan and Mine Run, November 24-December 1, 1863. Meade found Sykes too slow when aggressive action was demanded and relieved him of command. The following spring, Sykes went to the Department of Kansas, April 20, 1864-June 7, 1865, being in command of the District of South Kansas, September 1-October 10, 1864.

Sykes was breveted to Brigadier-General, U. S. Army, March 13, 1865, for gallant and meritorious service at the Battle of Gettysburg; and breveted to Major-General, U. S. Army, March 13, 1865, for gallant and meritorious services in the field during the Rebellion. He was waiting orders, June 7, 1865 to January 15, 1866; and in command of detachment of Recruits for New Mexico, March 2-August 12, 1866. He served in command of Regiment at Ft. Sumner, NM, August 12, 1866-April 27, 1867; of the District of New Mexico, March 27-April 27, 1867; and of Ft. Sumner, NM, April-June, 1867. He was on leave of absence, June-August, 1867; a Member of Examining Board, New York City, August-December, 1867; awaiting orders, January- March, 1868. He was promoted to Colonel, 20th Infantry, January 12, 1868. He was in command of Regiment at Baton Rouge, LA, March 20, 1868- April, 1869; of the District of Minnesota, April 20, 1869-June 15, 1873; of Ft. Snelling, MN, September 20, 1873-December 20, 1877; and of the District of the Rio Grande, and Ft. Brown, TX, December 27, 1877- February 8, 1880.

He died on February 8, 1880, at Ft. Brown, TX, aged 57 years. General George B. McClellan, who had known Sykes from their days at West Point, said of him: "As a gentleman his character was the highest, also the purest, and he endeared himself to all who were so fortunate as to be associated with him. As a soldier his record was one that all might be too glad to possess."