The first of the Northern forces to arrive on the scene of battle was the XVIII Corps of the Army of the James, which had fought at Cold Harbor. Early in the morning of June 15, these troops, commanded by Maj. Gen. W. F. “Baldy” Smith, crossed from Bermuda Hundred to the south side of the Appomattox by means of a pontoon bridge at Broadway Landing. Eighteen thousand Union soldiers were on their way to face less than 4,000 under Beauregard. Throughout the day they approached the city and assembled for the attack. [Illustration: _Gen. P. G. T. Beauregard, Confederate commander at Petersburg during the early days of the campaign, defended the “Dimmock Line” against the Federal assaults of June 15-18, 1864. When Lee arrived to direct operations, Beauregard’s troops were merged with the Army of Northern Virginia._] There was skirmishing throughout the afternoon as the Federals drove in the Confederate pickets, and shortly after 7 p.m. on June 15 the XVIII Corps launched a fierce attack on the Dimmock Line. Among the first points to fall was Battery 5, one of the strongest of the Confederate positions. Within a few hours Beauregard had lost not only Battery 5 but all the line for more than a mile south. The defenders withdrew and threw up a hasty entrenchment behind Harrison’s Creek, well to the rear of the captured section of the line. While the Confederate retreat was taking place, the Union II Corps, commanded by Maj. Gen. Winfield S. Hancock, arrived to reinforce the Federal columns. The appearance on the field of the II Corps was an ominous sign for the Confederates. While the initial attacks were taking place on June 15, the Army of the Potomac had been busily engaged in crossing the James River farther to the east. The number of Union troops south of the river was increasing hourly, until by midnight of June 16 at least 70,000 had crossed. Darkness ended the fighting on June 15, but early the next day the attacks were renewed. More of the defense line, south of the portion captured the previous day, now gave way. In response to repeated entreaties from Beauregard throughout June 15 and 16, Lee ordered more divisions to the support of Petersburg, necessitating the draining of precious reserves from the Richmond lines. By dawn of that second day, Beauregard could muster about 14,000 men to face the enemy. Thus, the center of attention rapidly shifted from Richmond to Petersburg, which had so recently seemed of but secondary importance. [Illustration: _Broadway Landing on the Appomattox River where Maj. Gen. W. F. “Baldy” Smith’s XVIII Corps of the Army of the James crossed on June 15, 1864. It was later used as an ordnance depot by the Union Army._] [Illustration: _Pontoon bridge at Broadway Landing constructed by Federal soldiers in 1864._]