In the early fall of 1862, a distance of not more than thirty miles lay between the Army of the Potomac and the Army of North Virginia. A state of uncertainty had existed for several weeks succeeding the battle of Sharpsburg, but the movements which resulted in the battle of Fredericksburg began to take shape when on the 5th of November the order was issued that removed General McClellan from command of the Federal forces and installed General Burnside in that position.
The order assigning General Burnside to command was received at General Lee's headquarters, then at Culpepper Court House, about twenty-four hours after it reached Warrenton, though not through official courtesy. General Lee, on receiving the news, said he regretted to part with McClellan, "For," he added, "we always understood each other so well, I fear they may continue to make these changes till they find someone whom I don't understand."
The Federal Army was encamped around Warrenton, Virginia, and was soon divided into three grand divisions whose commanders were Generals Sumner, Hooker, and Franklin.
Lee's army was on the opposite side of the Rappahannock River, divided into two corps, the First commanded by myself and the Second commanded by General Stonewall Jackson. At that time the Confederate Army extended from Culpepper Court House (where the First Corps was stationed) on it right across the Blue Ridge down the Valley of Virginia to Winchester. There Jackson was encamped with the Second Corps, except one division which was stationed at Chester Gap on the Blue Ridge Mountains.
About the 18th or 19th of November, we received information through our scouts that Sumner with his grand division of more than thirty thousand men, was moving towards Fredericksburg. Evidently he intended to surprise us and cross the Rappahannock before we could offer resistance. On receipt of the information, two of my divisions were ordered down to meet him. We made a forced march and arrived on the hills around Fredericksburg about three o'clock on the afternoon of the 21st. Sumner had already arrived and his army was encamped on Stafford Heights, overlooking the town from the Federal side. Before I reached Fredericksburg, General Patrick, provost-marshal general, crossed the river under a flag of truce and put the people in a state of great excitement by delivering the following letter: