The United States 32nd Infantry Division was formed from Army National Guard units from Wisconsin and Michigan and fought primarily during World War I and World War II. With roots as the Iron Brigade in the American Civil War, 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 Hindenburg Line 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. During World War II, the division was credited with many "firsts". It was the first United States division to deploy as an entire unit overseas and among the first of seven U.S. Army and U.S. Marine units to engage in offensive ground combat operations during 1942. The division was among the first divisions to engage the enemy and were still fighting holdouts after the official Japanese surrender. The 32nd logged a total of 654 days of combat during World War II, more than any other United States Army division. The unit was inactivated in 1946 after occupation duty in Japan. During 1961, the division was called up for a one-year tour of service in the state of Washington during the Berlin Crisis. In 1967, the 32nd Infantry Division (now made up completely of units from Wisconsin) was inactivated and partially reorganized as the 32nd Infantry Brigade, the largest unit of the Wisconsin Army National Guard. World War I Activation, organization and training When the United States declared war on Germany on 11 April 1917, the Wisconsin Adjutant General ordered the Milwaukee troops to add a squadron, and Troop C and Troop D were added. The Guard units' Troop A and Troop B had been mustered out of federal service less than a year earlier on 20 October 1916 and 6 March 1917, respectively. The Adjutant General then directed the unit to add a new regiment, and the Second and Third Squadrons were formed as the First Wisconsin Cavalry, with units organized in various cities. Troop E commanded by Captain John S. Coney was formed in Kenosha on 10 May