The United States 32nd Infantry Division was formed from  units from  and  and fought primarily during  and . With roots as the  in the , the division's ancestral units came to be referred to as the Iron Jaw Division. During tough combat in France in World War I, it soon acquired from the French the nickname Les Terribles, referring to its fortitude in advancing over terrain others could not. It was the first allied division to pierce the German  of defense, and the 32nd then adopted its shoulder patch; a line shot through with a red arrow, to signify its tenacity in piercing the enemy line. It then became known as the Red Arrow Division.