On June 9, Major General Benjamin Butler dispatched about 4,500 cavalry and infantry against the 2,500 Confederate defenders of Petersburg. While Butler's infantry demonstrated against the outer line of entrenchments east of Petersburg, Kautz's cavalry division attempted to enter the city from the south via the Jerusalem Plank Road but was repulsed by Home Guards. Afterwards, Butler withdrew. This was called the battle of old men and young boys by local residents.
Army of the Potomac
On June 14 through June 17, the Army of the Potomac crossed the James River and began moving towards Petersburg to support and renew Butler's assaults. Marching from Cold Harbor, Meade's Army of the Potomac crossed the James River on transports and a 2,200-foot-long pontoon bridge at Windmill Point.
Butler's leading elements (XVIII Corps and Kautz's cavalry) crossed the Appomattox River at Windmill Point and attacked the Petersburg defenses on June 15. The 5,400 defenders of Petersburg under command of General P.G.T. Beauregard were driven from their first line of entrenchments back to Harrison Creek. After dark the XVIII Corps was relieved by the II Corps.
On June 16, the II Corps captured another section of the Confederate line; on the 17th, the IX Corps gained more ground. Beauregard stripped the Howlett Line (Bermuda Hundred) to defend the city, and Lee rushed reinforcements to Petersburg from the Army of Northern Virginia.
The Siege of Petersburg
The II, XI, and V Corps from right to left attacked on June 18 but was repulsed with heavy casualties. By now the Confederate works were heavily manned and the greatest opportunity to capture Petersburg without a siege was lost. The siege of Petersburg began.