The Charter for the National Guard lies in the United States Constitution, providing a dual state/federal role for the Guard. The "state" portion of the dual role designates the governor as commander in chief of the Guard in his or her own state. This allows the use of Guard personnel and units as he or she sees fit to provide for the security and well-being of the state's citizens and property. The "federal" portion of the dual role provides for personnel and units of the Guard to be called from the state into active federal service under control of the United States Government in time of national crisis.
Indiana militia units were called to federal duty for service in the Mexican War in the 1840s. Volunteer militia units were again called into federal service in the 1860s during the Civil War, in which thousands of Hoosiers served in all major military campaigns. Several units formed for in-state service and were known as the Indiana Legion. In 1895 the Legion was renamed the Indiana National Guard. Soon thereafter several regiments were again mobilized, this time for the short Spanish-American War of 1898.
In 1916 Indiana units were called for duty on the Mexican Border. In 1917 the entire National Guard was mobilized again for service in World War I. The majority of the new 38th (Cyclone) Division came from Indiana units that were eventually deployed to France. Indiana's 150th Field Artillery Regiment fought with distinction as part of the new 42nd (Rainbow) Division. During World War II, the 38th Infantry Division earned combat streamers for three campaigns in the southwest Pacific, including spearheading the landings on Luzon in the Philippines that regained the Bataan Peninsula from the Japanese. For that, General Douglas MacArthur christened the 38th as the "Avengers of Bataan." Indiana Air Guard units were mobilized and served during the Korean War of the early 1950s and the Berlin Crisis of the early 1960s. Company D (Ranger), 151st Infantry, was mobilized during the Vietnam War and earned the distinction as one of the most highly decorated combat units of the war. Personnel from four Army Guard and four Air Guard units from Indiana were called into federal service in support of Operations Desert Shield/Storm in the Middle East.
There are countless instances over the years in which the Governor of Indiana has called the Guard into state service for assistance in disaster relief or to help maintain law and order. During the worst tornadoes, flooding, blizzard conditions, failure of city and town utilities, aircraft crashes, domestic violence, and a host of other emergencies, it was, and will in the future be, the Indiana National Guard that has and will have the personnel, equipment, and training to respond immediately and professionally.