This is an analysis of combat operations of US First Army under the command of Courtney Hodges, between August 1 and September 12, 1944, with an emphasis upon 1st, 4th, 9th, and 30th Divisions. However, other formations are necessarily discussed in order to maintain context. Indeed, many historians have failed to emphasize the complex interdependent nature of these efforts, and the traditional narrative has been distorted by inadequate situational awareness. This study argues that the army's operations were exceedingly difficult, resulting in approximately 40,000 casualties over a six week period. Although historians claim that the Germans were essentially defeated by the end of July, and that the Allied advance was subsequently halted by logistical difficulties, the official combat records clarify that logistical shortages were a tertiary factor, as the enemy remained capable of strong resistance. Consequently, defensive efforts were the primary factor hindering the advance, in conjunction with deteriorating weather conditions, rugged terrain, and surprisingly severe traffic congestion. Although this was mobile warfare, military theorists have overestimated the effectiveness of mechanization and underestimated the potential for antitank defenses. Ultimately, this study asserts that First Army was the primary American combat formation, and historians have exaggerated the importance of George Patton's Third Army. Therefore, in order to understand an American way of war, the combat operations of First Army deserve far more attention than they have previously received. This narrative thus emphasizes forgotten battles, including: Tessy, St. Sever, Tete, Perriers, Mayenne, Ranes, Flers, Mace, Elbeuf, Mantes, Corbeil, Sevran, Mons, Cambrai, Philippeville, Dinant, and Aubel.