American Military History, Volume 2 by Richard W. Stewart

While ULTRA monitored the success of the Allied deception plan and Allied aircraft and French resistance fighters impeded the move- ment of those German reserves that did move to Normandy, the Allies quickly built up their strength and linked the beachheads. U.S. troops then moved against Cherbourg, taking the port after bitter fighting, three weeks following the invasion. Other Allied forces had in the meantime deepened the beachhead between Caen and the road center of St. Lô, so that by the end of June the most forward positions were twenty miles from the sea. The Germans still had been able to mount no major counterattack.

Commanded by Field Marshal Gerd von Rundstedt, the enemy nevertheless defended tenaciously in terrain ideally suited to the defense. This was hedgerow country, where through the centuries French farm- ers had erected high banks of earth around every small field to fence in livestock and protect crops from coastal winds. These banks were thick with the roots of shrubs and trees; and in many places, sunken roads screened by a canopy of tree branches ran between two hedgerows. Tun- neling into the hedgerows and using the sunken roads for lines of com- munication, the Germans had turned each field into a small fortress.