Second Battle of Petersburg The Second Battle of Petersburg , also known as the Assault on Petersburg , was fought June 15 – 18 , 1864 , at the beginning of the Richmond – Petersburg Campaign ( popularly known as the Siege of Petersburg ) . Union forces under Lt . Gen . Ulysses S . Grant attempted to capture Petersburg , Virginia , before Gen . Robert E . Lee ' s Confederate Army of Northern Virginia could reinforce the city . The four days included repeated Union assaults against substantially smaller forces commanded by Gen . P . G . T . Beauregard . Beauregard ' s strong defensive positions and poorly coordinated actions by the Union generals ( notably Maj . Gen . William F . " Baldy " Smith , who squandered the best opportunity for success on June 15 ) made up for the disparity in the sizes of the armies . By June 18 , the arrival of significant reinforcements from Lee ' s army made further assaults impractical . The failure of the Union to defeat the Confederates in these actions resulted in the start of the ten - month Siege of Petersburg . Background . The First Battle of Petersburg occurred on June 9 , 1864 , when Maj . Gen . Benjamin Butler dispatched 4 , 500 troops from his Army of the James in the Bermuda Hundred area and assaulted the Dimmock Line , the outer line of earthworks protecting Petersburg . The Confederates , under the overall command of Gen . P . G . T . Beauregard , numbered only 2 , 500 , many of whom were teenage boys and elderly men . Timid leadership on the part of Union Maj . Gen . Quincy A . Gillmore and Brig . Gen . August Kautz led to the failure of the assault , squandering a prime opportunity to seize lightly defended Petersburg . Butler ' s men returned to their positions in Bermuda Hundred . After the Battle of Cold Harbor in Lt . Gen . Ulysses S . Grant ' s 1864 Overland Campaign , the Union Army of the Potomac slipped away from Gen . Robert E . Lee and began crossing the James River . Although the Overland Campaign ' s objective had been to defeat Lee ' s Army of Northern Virginia in a decisive battle , Grant changed his objective to be the city of Petersburg , an important rail junction that controlled the supplies leading to the Confederate capital of Richmond . Grant knew that Lee could not protect Richmond if Petersburg fell and he would be forced to battle Grant in the open . He also knew from the unsuccessful first assaults on June 9 how weak the Petersburg defenses actually were . Speed was essential to Grant ' s plan , requiring success before Lee realized Grant ' s objective and could reinforce Petersburg . Lee was not in fact fully cognizant of Grant ' s moves until June 18 , assuming until then that Grant would target Richmond . Beauregard , however , had been loudly warning of the danger to Petersburg since June 9 . Inexplicably , Grant selected Butler ' s Army of the James , which had performed poorly in the Bermuda Hundred Campaign , to lead the expedition toward Petersburg . On June 14 he directed Butler to augment the XVIII Corps , commanded by Brig . Gen . William F . " Baldy " Smith , to a strength of 16 , 000 men , including Kautz ' s cavalry division , and use the same route employed in the unsuccessful attacks of June 9 . The II Corps of the Army of the Potomac , commanded by Maj . Gen . Winfield S . Hancock , would follow Smith . Grant wrote in his post - war memoirs , " I believed then , and still believe , that Petersburg could have been easily captured at that time . " One advantage for the Confederates was the strength of the Dimmock Line , formidable artillery positions connected by earthworks and trenches for over , circling the city and anchored on the Appomattox River to the east and west . Since Beauregard had insufficient men available to defend the entire line , he concentrated 2 , 200 troops under Brig . Gen . Henry A . Wise in the northeastern sector , between Redan number 1 on the Appomattox River and Redan number 23 , protecting the Norfolk and Petersburg Railroad to the southeast . Even with his concentration , infantrymen were spaced an unacceptable apart . His remaining 3 , 200 men were facing Butler ' s army at Bermuda Hundred . Battle . June 15 . Baldy Smith and his men crossed the Appomattox shortly after dawn on June 15 . His force consisted of the infantry divisions of Brig . Gens . William T . H . Brooks , John H . Martindale , and Edward W . Hinks , and the cavalry division of Brig . Gen . August Kautz . The transport vessels delivered these divisions almost at random to landing sites on the opposite shore , confusing Smith ' s plans and wasting time reorganizing . Kautz ' s cavalry division was ordered to clear the line of advance for the infantry , Brooks and Martindale would march down the City Point Railroad , and Hinks ' s U . S . Colored Troops would approach on the Jordan Point Road . Delays in the advance continued after the landing . The cavalry encountered an unexpected stronghold at Baylor ' s farm northeast of Petersburg . Hinks ' s men launched two attacks on the Confederates and captured a cannon , but the overall advance was delayed until early afternoon . Smith performed a reconnaissance and , despite his sense of nervousness about the strength of the enemy position , planned to carry the defensive works with a strong skirmish line . He was delayed again when his artillery commander allowed all of the horses to be watered simultaneously , making it impossible to bring up his guns until about 7 p . m . While Smith was delaying , Kautz reached the railroad near Redan number 20 on the right flank of the Confederate line around noon . Approximately 600 Confederates under Brig . Gen . James Dearing bombarded Kautz with artillery and the Union cavalrymen got no closer than from the line . In a manner similar to the July 9 battle , Kautz listened for evidence that Smith was attacking to his right and , hearing none , gave up and withdrew . When Smith finally started his attack , his skirmishers swept over the earthworks on a front , capturing Batteries 3 and 5 – 11 , causing the Confederates to retreat to a weaker defensive line on Harrison ' s Creek . Despite this initial success and the prospect of a virtually undefended city immediately to his front , Smith decided to wait until dawn to resume his attack . By this time Winfield Hancock had arrived at Smith ' s headquarters . The normally decisive and pugnacious Hancock , who outranked Smith , was uncertain of his orders and the disposition of forces , and uncharacteristically deferred to Smith ' s judgment to wait . Smith ' s timid service on June 15 would turn out to be his last combat command . Butler indirectly accused Smith of " dilatoriness " and the dispute escalated to Grant . Although Grant originally contemplated replacing Butler by Smith as commander of the Army of the James , he eventually retained Butler and reassigned Smith to New York to await further orders , which were never issued . Beauregard wrote later that Petersburg " at that hour was clearly at the mercy of the Federal commander , who had all but captured it . " But he used the time he had been granted to good advantage . Receiving no guidance from Richmond in response to his urgent requests , he unilaterally decided to strip his defenses from the Howlett Line , which was bottling up Butler ' s army in Bermuda Hundred , making the divisions of Maj . Gens . Robert Hoke and Bushrod Johnson available for the new Petersburg defensive line . Butler might have used this opportunity to move his army between Petersburg and Richmond , which would have doomed the Confederate capital , but he once again failed to act . June 16 . By the morning of June 16 , Beauregard had concentrated about 14 , 000 men in his defensive line , but this paled in comparison to the 50 , 000 Federals that now faced him . Grant had arrived with Maj . Gen . Ambrose Burnside ' s IX Corps , addressed the confusion of Hancock ' s orders , and ordered a reconnaissance for weak points in the defensive line . Hancock , in temporary command of the Army of the Potomac until Maj . Gen . George G . Meade arrived , prepared Smith ' s XVIII Corps on the right , his own II Corps in the center , and Burnside ' s IX Corps on the left . Hancock ' s assault began around 5 : 30 p . m . as all three corps moved slowly forward . Beauregard ' s men fought fiercely , erecting new breastworks to the rear as breakthroughs occurred . Upon the arrival of General Meade , a second attack was ordered and Brig . Gen . Francis C . Barlow led his division against Redans 13 , 14 , and 15 . Confederate artillery fire caused significant Union casualties , including the death of Col . Patrick Kelly , commander of the famous Irish Brigade . Although Barlow ' s men managed to capture their objectives , a counterattack drove them back , taking numerous Union prisoners . The survivors dug in close to the enemy works . June 17 . June 17 was a day of uncoordinated Union attacks , starting on the left flank where two brigades of Burnside ' s IX Corps under Brig . Gen . Robert B . Potter stealthily approached the Confederate line and launched a surprise attack at dawn . Initially successful , it captured nearly a mile of the Confederate fortifications and about 600 prisoners , but the effort eventually failed when Potter ' s men moved forward to find another line of entrenchments . Their mobility was limited because of tangled logs in a ravine behind them and Confederate guns were able to strike them with enfilade fire . At 2 p . m . , the IX Corps launched a second attack , led by the brigade of Brig . Gen . John F . Hartranft . They were somehow sent forward at a right angle to the Confederate line , which left them vulnerable to enfilading fire . In the evening , Brig . Gen . James H . Ledlie ' s division also failed in its assault , during which Ledlie was observed to be drunk ( a behavioral pattern that would repeat itself notoriously at the Battle of the Crater ) . During the day , Beauregard ' s engineers had laid out new defensive positions a mile to the west of the Dimmock Line , running along a creek named Taylor ' s Branch to the Appomattox . Late that night the Confederates pulled back to their new position . Beauregard expressed his frustration with the lack of support or concern from Robert E . Lee , writing years after the war , " The Army of Northern Virginia was yet far distant , and I had failed to convince its distinguished commander of the fact that I was then fighting Grant ' s whole army with less than eleven thousand men . " Lee had systematically ignored all of Beauregard ' s pleas and it was not until his own son , cavalry Maj . Gen . W . H . F . " Rooney " Lee , had verified Grant ' s movements across the river , that he acknowledged the current perilous situation at Petersburg . He immediately dispatched two divisions of his men , exhausted from the Overland Campaign , to Petersburg , beginning at 3 a . m . on June 18 . June 18 . With the arrival of Lee ' s two divisions , under Maj . Gen . Joseph B . Kershaw and Charles W . Field , Beauregard had over 20 , 000 men to defend the city , but Grant ' s force had been augmented by the arrival of Maj . Gen . Gouverneur K . Warren ' s V Corps and 67 , 000 Federals were present . The first Union attack began at dawn , started by the II and XVIII Corps on the Union right . Hancock began to suffer effects from his lingering Gettysburg wound and he turned over command of the II Corps to Maj . Gen . David B . Birney . The men of the II Corps were surprised to make rapid progress against the Confederate line , not realizing that Beauregard had moved it back the night before . When they encountered the second line , the attack immediately ground to a halt and the corps suffered under heavy Confederate fire for hours . By noon , the IX and V Corps , which had a longer distance to march to join the attack , came up alongside the II Corps . Maj . Gen . Orlando B . Willcox ' s division of the IX Corps led a renewed attack but it suffered significant losses in the marsh and open fields crossed by Taylor ' s Branch . Willcox ' s division emerged with only 1 , 000 men standing . Warren ' s V Corps was halted by murderous fire from Rives ' s Salient ( also known as Battery 27 , the position where the Dimmock Line crossed the Jerusalem Plank Road , present - day U . S . Route 301 ) , an attack in which Colonel Joshua Lawrence Chamberlain , commanding the First Brigade , First Division , V Corps , was severely wounded . His wound was believed to be mortal and Chamberlain was granted , a battlefield promotion to brigadier general by General Grant . At 6 : 30 p . m . , Meade ordered a final assault , which also failed with more horrendous losses . One of the leading regiments was the 1st Maine Heavy Artillery , 900 men that had been converted from essentially garrison duty manning artillery to be infantrymen at the start of the Overland Campaign . The regiment quickly lost 632 men in the assault , the heaviest single - battle loss of any regiment during the entire war . Aftermath . Having achieved almost no gains from four days of assaults , Meade ordered his army to dig in . Union casualties were 11 , 386 ( 1 , 688 killed , 8 , 513 wounded , 1 , 185 missing or captured ) , Confederate 4 , 000 ( 200 killed , 2 , 900 wounded , 900 missing or captured ) . Grant ' s opportunity to take Petersburg easily was lost , but Lee , who arrived at Petersburg around noon on June 18 , was unable to prevent the Union army from laying siege to the city . The siege would last until April 1865 .