First Corps , Army of Northern Virginia The First Corps , Army of Northern Virginia ( or Longstreet ' s Corps ) was a military unit fighting for the Confederate States of America in the American Civil War . It was formed in early 1861 and served until the spring of 1865 , mostly in the Eastern Theater . The corps was commanded by James Longstreet for much of its existence . In part or as a whole , the corps fought in nearly all of the major battles in the Eastern Theater , such as Fredericksburg , Gettysburg , The Wilderness , Cold Harbor , and the Siege of Petersburg . The corps also fought in Tennessee and performed important forage service in Suffolk , Virginia . It was disbanded shortly following Gen . Robert E . Lee ' s surrender to Union forces April 9 , 1865 . Origins . On June 1 , 1862 , Robert E . Lee took command of the Army of the Potomac following Johnston ' s wounding during Battle of Seven Pines , and shortly afterwards this army would be known as the Army of Northern Virginia . Lee re - organized the army as two " wings " ( corps were not legally allowed by the Confederate Congress until September 18 ) , with Longstreet in charge of the Left Wing and Lt . Gen . Thomas J . " Stonewall " Jackson in charge of the Right Wing . With the authorization of corps later that year , the Left Wing was redesignated as the First Corps . At this time , Longstreet ' s corps contained twenty - one brigades organized into five divisions under major generals Lafayette McLaws , Richard H . Anderson , George E . Pickett , and John B . Hood , and Brigadier General Robert Ranson , Jr . 1862 . Fredericksburg . Note : see Fredericksburg order of battle for the command structure of the Army of Northern Virginia at this time . The Battle of Fredericksburg was fought in and around Fredericksburg , Virginia , starting on December 11 and concluding December 15 , 1862 , between Lee ' s Army of Northern Virginia and the Federal Army of the Potomac , now commanded by Maj . Gen . Ambrose E . Burnside . The First Corps started reaching Marye ' s Heights on November 18 and deployed there to contest a possible pontoon crossing of the Union army at Fredericksburg , with the Second Corps following quickly once Lee was more certain of Burnside ' s intentions . Until Lee was convinced , the First Corps did not deeply entrench until a couple of weeks before the actions on December 12 . After Jackson ' s arrival on December 2 , Longstreet started entrenching along his portion of the line , with Anderson ' s division near Banks Ford on the Rappahannock and the remaining divisions on Marye ' s Heights ; the artillery was placed along the crest of the ridge by lieutenant colonel Edward Portor Alexander . When Burnside ' s army started bridging the Rappahannock at Fredericksburg in the early morning of December 11 , their crossing was contested by William Barksdale ' s brigade , which was scattered along the city ' s riverfront . The Confederates started firing at the Union pontooners shortly after 5 a . m . , forcing them to abandon their work ; Union artillery fire from Strafford Heights on the eastern side of the river was unable to drive Barksdale ' s brigade from their positions , despite several hours of bombardment . About 3 p . m . , small groups of Union soldiers were ferried across the river by the engineers and drove the Confederates through the city . Barksdale withdrew to the main Confederate positions shortly after 7 p . m . In January 1863 , Ransom ' s division was transferred to North Carolina . 1863 . Suffolk operations and Chancellorsville . Longstreet and part of the First Corps ( with Hood ' s and Pickett ' s divisions ) were detached from the Army of Northern Virginia on February 26 and sent to Suffolk , Virginia , to contend with the Federal pressure there from the Union IX Corps , as well as allow supplies in the region to be collected by Confederate authorities . During the next several months , Longstreet would serve as head of the Department of Virginia and North Carolina . Starting on April 11 , Longstreet used his two First Corps division to lay siege to Suffolk , in order to better collect supplies in the area near the city . After three weeks , Longstreet was ordered to abandon the siege and return to Lee ' s main army but the Battle of Chancellorsville ended before Longstreet arrived . Gettysburg . Note : see Gettysburg order of battle for the command structure of the Army of Northern Virginia at this time . Following the death of Jackson in May , the Army of Northern Virginia was reorgainized into three corps . Longstreet retained McLaws ' , Hood ' s , and Pickett ' s divisions , while Richard Anderson ' s division was transferred to the new Third Corps commanded by A . P . Hill . Two of Pickett ' s brigades were detached to help the Confederate forces in North Carolina and near Richmond , leaving only three brigades in his division . Nearing the end of June 1863 the Army of Northern Virginia had passed up the Shenandoah Valley , crossed through Maryland and entered Pennsylvania , using the Blue Ridge Mountains to hide their movements from Union cavalry patrol s . The First Corps started crossing the Potomac River into Maryland on June 25 , finishing the following day ; the corps then camped for several days near Chambersburg , Pennsylvania . Chickamauga . Note : see Chickamauga order of battle for the command structure of the Army of Tennessee at this time . On September 9 , the First Corps was transferred to the Department of Tennessee , except for Pickett ' s division and the brigade of " Tige " Anderson . The Tennessee rail hub at Chattanooga was the primary goal of both armies in the West , these being the Army of the Cumberland under Union Maj . Gen . Rosecrans and numbering nearly 60 , 000 men , and the Army of Tennessee led by Confederate Gen . Braxton Bragg and the First Corps along with additional reinforcements would constitute over 65 , 000 troops . To get to and reinforce Bragg ' s army , the First Corps would use 16 railroads on a nearly 800 - mile ( 1 , 350 km ) route through the North and South Carolina to reach the Army of Tennessee , stationed in northern Georgia . This round - about route was necessary due to the different gauges of the surviving Southern rail system between the forces , and would take three weeks to complete . The lead elements of Longstreet ' s Corps , three brigades of Maj . Gen . John Bell Hood ' s Division , were grouped with a western division under Brig . Gen . Bushrod Johnson and opened the battle on September 18 by crossing Chickamauga Creek at Reed ' s Bridge . Since Longstreet had not yet arrived , Hood assumed command of the corps while Brig . Gen . Evander Law assumed command of Hood ' s Division . The First Corps would fight in the same formation the next day on the Confederate left . On September 20 , Longstreet arrived along with two brigades from McLaws ' Division . Since McLaws had not yet arrived , the brigades were led by Brig . Gen . Joseph Kershaw . Bragg used the arrival of Longstreet to reorganize his army into wings , with Longstreet commanding the left wing consisting of his own corps under Hood , Buckner ' s Corps , and Hindman ' s Division while Leonidas Polk assumed command of the right . The troops of the First Corps played an important role in the breakthrough Longstreet achieved on the 20th . This fight is considered the most significant Union defeat in the Western Theater , with total casualties on both sides exceeding 34 , 000 . Winter quarters 1863 – 64 . About an hour after the failed attack on Fort Sanders on November 29 , a telegram from President Jefferson Davis arrived , informing Longstreet of Bragg ' s defeat at Chattanooga and directing the First Corps to rejoin the Army of Tennessee . At first Longstreet decided to leave the Knoxville area immediately , so he directed the wagon train to move rearward at once . Then two messages from Bragg came in , suggesting the First Corps should cross the mountain ranges into Georgia to reach the army retreating there . As Longstreet held councils of war with his senior officers , the logistical problems of crossing the mountains came to light , and it was decided to stay at Knoxville until Union reinforcements arrived then go into winter quarters near Bristol , Virginia . On December 1 Confederate cavalry patrols captured an enemy courier , carrying a message for Burnside stating three columns had been sent to his aid . Longstreet acted on this information — later proved to be a ruse — and ordered his wagons started eastward under guard . The 15 , 000 infantrymen began to follow late in the day on December 4 , marching in a heavy rain all night . Over the next four days the First Corps retreated toward Virginia , passing through Bean ' s Station and heading for Rogersville in Hawkins County , Tennessee , where Longstreet halted on December 9 . The following day he received discretionary authority from Davis covering all soldiers in his region , and with this he recalled the cavalry units that had been ordered to Bragg in Georgia . Longstreet rested his command at Rogersville until December 13 , when he learned of pursuing Union infantry and cavalry back at Bean ' s Station ; he then decided to turn and attack them the next day . Civil War service , 1864 . Overland Campaign . Note : see Wilderness order of battle for the command structure of the Army of Northern Virginia at this time . At the start of the Overland Campaign , the First Corps was 25 miles ( 40 km ) away guarding rail lines at Gordonsville when the rest of Lee ' s army engaged the Meade ' s Army of the Potomac in the Battle of the Wilderness on May 5 . Longstreet received orders telling him to reunite with the rest of the army and support A . P . Hill ' s Third Corps before 4 a . m . on May 4 . By mid - day on May 6 the Third Corps was in danger of being swamped over by the Union II Corps when the First Corps arrived to fill in the gap created by the fight . Longstreet put in his men directly against the now - worn out II Corps and regained almost all of the ground lost in the battle so far , then pushed the II Corps a mile ( 1 . 6 km ) further . Shortly after stabalizing the Confederate line , a Confederate engineer discovered an unfinished railroad bed which gave the Confederates access to the Union left flank . Longstreet orgainized a flanking force composed of four brigades drawn from his own First Corps and from the Third Corps . While the initial attack was successful in routing the Union flank , the Confederates quickly became confused in the dense thickets . At this time , Longstreet was seriously wounded in his neck by friendly fire . Command of the First Corps temporarily passed to Charles Field , who then reorgainized the corps into a defensive line . On May 7 , Lee decided to replace Field with Richard Anderson . The Battle of Spotsylvania Court House was fought May 8 – 21 , along a trench line four miles long , in and around Spotsylvania , about 10 miles southeast of the Wilderness battlefields . On the evening of May 7 , Lee ordered Maj . Gen . Richard Anderson to move his corps to Spotsylvania Court House , believing that Grant was headed to the same place . He told Anderson to have his men on the move by three in the morning , but Anderson decided to move at ten that evening , a decision that would prove to help the Army of Northern Virginia considerably . At the same time Lee put Anderson in motion , Grant decided to move his army to the same location in hopes of drawing Lee out into the open and get between Lee and Richmond . The First Corps had just arrived to Block House Bridge when Anderson was informed that Maj . Gen . J . E . B . Stuart was holding off Grant ’ s infantry ( elements of Warren ’ s V Corps ) on Brock Road and needed reinforcements . He sent the brigades of Henegan and Humphreys to his aid , and upon their arrival , Stuart deployed them along the crest of Laurel Hill , where they successfully held off the Federal advance . No sooner had Anderson sent his first two brigades off when he was approached by a courier from Maj . Gen . Fitzhugh Lee , who was engaged with Federal cavalry units of Brig . Gen . James H . Wilson , who had just broken through to the Court House . Anderson immediately sent the brigades of Bryan and Wofford , who are able to help Lee fend off the cavalrymen . The First Corps would spend the majority of the battle defending against repeated assaults of Laurel Hill made by both V Corps infantry as well as units from Hancock ’ s II Corps , and was not heavily involved in the fighting in and around the “ Bloody Angle . ” Civil War service , 1865 . Five Forks and Appomattox . Following Lt . Gen . A . P . Hill ' s death at Petersburg , the Third Corps was merged with the First on April 2 .