Gouverneur K . Warren Gouverneur Kemble Warren ( January 8 , 1830 – August 8 , 1882 ) was a civil engineer and prominent general in the Union Army during the American Civil War . He is best remembered for arranging the last - minute defense of Little Round Top during the Battle of Gettysburg and is often referred to as the " Hero of Little Round Top . " His subsequent service as a corps commander and his remaining military career were ruined during the Battle of Five Forks , when he was relieved of command by Philip Sheridan . Early life . Warren was born in Cold Spring , Putnam County , New York , and named for Gouverneur Kemble , a prominent local Congressman , diplomat , and industrialist . His sister , Emily Warren Roebling , would later play a significant role in the building of the Brooklyn Bridge . He entered the United States Military Academy at age 16 and graduated second in his class of 44 cadets in 1850 . He was commissioned a brevet second lieutenant in the Corps of Topographical Engineers . In the antebellum years he worked on the Mississippi River , on transcontinental railroad surveys , and mapped the trans - Mississippi West . He served as the engineer on William S . Harney ' s Battle of Ash Hollow in the Nebraska Territory in 1855 , where he saw his first combat . He took part in studies of possible transcontinental railroad routes , creating the first comprehensive map of the United States west of the Mississippi in 1857 . This required extensive explorations of the vast Nebraska Territory , including Nebraska , North Dakota , South Dakota , part of Montana , and part of Wyoming . One region he surveyed was the Minnesota River Valley , a valley much larger than what would be expected from the low - flow Minnesota River . In some places the valley is 5 miles ( 8 km ) wide and 250 feet ( 80 m ) deep . Warren first explained the hydrology of the region in 1868 , attributing the gorge to a massive river , which drained Lake Agassiz between 11 , 700 and 9 , 400 years ago . The great river was named glacial River Warren in his honor after his death . Civil War . At the start of the war , Warren was a first lieutenant and mathematics instructor at the United States Military Academy at West Point , across the Hudson River from his hometown . He helped raise a local regiment for service in the Union Army and was appointed lieutenant colonel of the 5th New York Infantry on May 14 , 1861 . Warren and his regiment saw their first combat at the Battle of Big Bethel in Virginia on June 10 , arguably the first major land engagement of the war . He was promoted to colonel and regimental commander on September 10 . In the 1862 Peninsula Campaign , Warren commanded his regiment at the Siege of Yorktown and also assisted the chief topographical engineer of the Army of the Potomac , Brig . Gen . Andrew A . Humphreys , by leading reconnaissance missions and drawing detailed maps of appropriate routes for the army in its advance up the Virginia Peninsula . He commanded a brigade ( 3rd Brigade , 2nd Division , V Corps ) during the Seven Days Battles and was wounded in the knee at the Battle of Gaines ' Mill , although he refused to be taken from the field . At the Battle of Malvern Hill , his brigade stopped the attack of a Confederate division . He continued to lead the brigade at the Second Battle of Bull Run , suffering heavy casualties in a heroic stand against an overwhelming enemy assault , and at Antietam , where V Corps was in reserve and saw no combat . Warren was promoted to brigadier general on September 26 , 1862 , and he and his brigade fought in the Battle of Fredericksburg in December . When Maj . Gen . Joseph Hooker reorganized the Army of the Potomac in February 1863 , he named Warren his chief topographical engineer and then chief engineer . As chief engineer , Warren was commended for his service in the Battle of Chancellorsville . At the start of the Gettysburg Campaign , as Confederate General Robert E . Lee began his invasion of Pennsylvania , Warren advised Hooker on the routes the Army should take in pursuit . On the second day of the Battle of Gettysburg , July 2 , 1863 , Warren initiated the defense of Little Round Top , recognizing the importance of the undefended position on the left flank of the Union Army , and directing , on his own initiative , the brigade of Colonel Strong Vincent to occupy it just minutes before it was attacked . Warren suffered a minor neck wound during the Confederate assault . Promoted to major general after Gettysburg ( August 8 , 1863 ) , Warren commanded II Corps from August 1863 until March 1864 , replacing the wounded Maj . Gen . Winfield S . Hancock , and distinguishing himself at the Battle of Bristoe Station . On March 13 , 1865 , he was breveted to major general in the regular army for his actions at Bristoe Station . During the Mine Run Campaign , Warren ' s corps was ordered to attack Lee ' s army , but he perceived that a trap had been laid and refused the order from army commander Maj . Gen . George G . Meade . Although initially angry at Warren , Meade acknowledged that he had been right . Upon Hancock ' s return from medical leave , and the spring 1864 reorganization of the Army of the Potomac , Warren assumed command of the V Corps and led it through the Overland Campaign , the Siege of Petersburg , and the Appomattox Campaign . During these Virginia campaigns , Warren established a reputation of bringing his engineering traits of deliberation and caution to the role of infantry corps commander . He won the Battle of Globe Tavern , August 18 to August 20 , 1864 , cutting the Weldon Railroad , a vital supply route north to Petersburg . He also won a limited success in the Battle of Peebles ' Farm in September 1864 , carrying a part of the Confederate lines protecting supplies moving to Petersburg on the Boydton Plank Road . The aggressive Maj . Gen . Philip Sheridan , a key subordinate of Lt . Gen . Ulysses S . Grant , was dissatisfied with Warren ' s performance . He was angry at Warren ' s corps for supposedly obstructing roads after the Battle of the Wilderness and its cautious actions during the Siege of Petersburg . At the beginning of the Appomattox Campaign , Sheridan requested that the VI Corps be assigned to his pursuit of Lee ' s army , but Grant insisted that the V Corps was better positioned . He gave Sheridan written permission to relieve Warren if he felt it was justified " for the good of the service . " Grant later wrote in his " Personal Memoirs " , At the Battle of Five Forks on April 1 , 1865 , Sheridan became enraged with Warren ' s performance . He perceived that the V Corps moved too slowly into the attack and faulted Warren for not being at the front of his columns when Sheridan went to confront him . Warren in fact was handling dispositions of his divisions in a manner consistent with that of a corps commander , and the attack by the V Corps carried the day at Five Forks , arguably the pivotal battle in the final days against Lee ' s army . Nevertheless , Sheridan relieved Warren of command on the spot . He was assigned to the defenses of Petersburg and then briefly to command of the Department of Mississippi . Postbellum career . Humiliated by Sheridan , Warren resigned his commission as major general of volunteers in protest on May 27 , 1865 , reverting to his permanent rank as major in the Corps of Engineers . He served as an engineer for seventeen years , building railroads , with assignments along the Mississippi River , achieving the rank of lieutenant colonel in 1879 . But the career that had shown so much promise at Gettysburg was ruined . He urgently requested a court of inquiry to exonerate him from the stigma of Sheridan ' s action . Numerous requests were ignored or refused until Ulysses S . Grant retired from the presidency . President Rutherford B . Hayes ordered a court of inquiry that convened in 1879 and , after hearing testimony from dozens of witnesses over 100 days , found that Sheridan ' s relief of Warren had been unjustified . Unfortunately for Warren , these results were not published until after his death . Warren ' s last assignment in the Army was as district engineer for Newport , Rhode Island , where he died in 1882 . He was buried in the Island Cemetery in Newport in civilian clothes and without military honors at his own request . His last words were , " The flag ! The flag ! " In memoriam . A bronze statue of Warren stands on Little Round Top in Gettysburg National Military Park . It was created by Karl Gerhardt ( 1853 – 1940 ) and dedicated in 1888 . Another bronze statue , by Henry Baerer ( 1837 – 1908 ) , was erected in the Grand Army Plaza , Brooklyn , New York . It depicts Warren standing in uniform , with field binoculars on a granite pedestal , made of stone quarried at Little Round Top . The G . K . Warren Prize is awarded approximately every four years by the National Academy of Sciences . It is funded by a gift from his daughter , Miss Emily B . Warren , in memory of her father .