Brig. Gen. Douglas MacArthur was a pivotal figure in

Brig. Gen. Douglas MacArthur was a pivotal figure in the formation of the National Guard’s 42nd “Rainbow Division” for combat service in World War I. The division was made up of National Guard elements from 26 states and the District of Columbia. MacArthur originally served as the division chief of staff and went on to command the 84th Brigade during the American Expeditionary Force 100 days offensive that brought an end to World War I, fighting in St. Mihiel in September and the Meuse-Argonne campaign in October and November. Photo courtesy of the New York State Military History Museum.