The Union Army began marching on [[November 15]], andanD the first elements arrived in Falmouth on [[November 17]]. Burnside's plan quickly went awry—he had ordered pontoon bridges to be sent to the front and assembled for his quick crossing of the Rappahannock, but because of administrative bungling, the bridges had not preceded the army. As Sumner arrived, he strongly urged an immediate crossing of the river to scatter the token Confederate force of 500 men in the town and occupying the commanding heights to the west. Burnside began to panic, worried that the increasing autumn rains would make the fording points unusable and that Sumner might be cut off and destroyed. He squandered his initiative and ordered Sumner to wait in Falmouth. Para el [[November 21]] las tropas del Tte. Gen. [[James Longstreet]] habían arribado a a las cercanías de
Fredericksburg y las de Jackson (corriente abajo a lo largo del Rappahannock para evitar cruzarlo)las siguieron rápidamente.
