See the map here: https://www.backtonormandy.org/from-d-day-to-paris/3666-d-day-plus-25-42.html
Breakout from Normandy required infantrymen fighting through a dense and difficult perimeter of marshes and bocage to reach ground suitable for mechanized warfare.
In the American sector, such ground ran roughly from Coutances through Saint-Lô to Caumont-l’Êventé.
The 79th and 90th Infantry Divisions, supported for a time by the 82nd Airborne Division and then by the 8th Infantry Division, battled down the west coast to seize La Haye-du-Puits and approach Coutances.
The 83rd and 4th Infantry Divisions battered their way forward from Carentan to the outskirts of Périers.
The 9th and 30th Infantry Divisions opened a route from Carentan to Saint-Lô, while the 2nd Infantry Division seized Hill192 overlooking Saint-Lô from the east.
The 35th and 29th Infantry Divisions fought to the outskirts of Saint-Lô, and the 29th forced its way into the city itself.
The 2nd, 3rd and the newly arrived 4th Armored Divisions supported these offensives with detachments and the 1st and then the 5th Infantry Divisions conducted aggressive defenses around Caumont-l’Êventé.
By 18 July the American Army was clear of the worst of the marshes and bocage and suitably positioned for mechanized warfare.
To their east Commonwealth Forces fought their way into Caen.
The 82nd and 101st Airborne Divisions withdrew to England to prepare for further airborne operations.