As the above view shows, the Federals had a monumental task ahead of them. The Army of the Potomac's newest commanding General, Ambrose E. Burnside, believed that his predecessor, Major General George B. McClellan, was relieved of his command due to his inaction after Antietam. Burnside had planned on stealing a march on General Lee and moving on Richmond. However, despite initially slipping away from Lee's Army of Northern Virginia, when Burnside arrived at Fredericksburg, the pontoons he had order to allow him to cross the Rappahannock had not yet arrived. As he waited, General Lee moved his Army onto the heights west of town. With his left flank anchored on the river and his right on Prospect Hill, Burnside saw that he had few options. Washington expected action or he may meet McClellan's fate. To maintain the initiative, he decided on a frontal assault. It would cost the Union thousands.