The Hall of Flags examines early Oklahoma Military History. A series of exhibits within the hall will take you from the beginning of Oklahoma’s military history through the Forts and along the trails of Indian Territory. Explore the role of the Indian Police, and learn about Oklahoma’s Civil War battles. An examination of the Spanish American War and Mexican Border cases explains the formation of the 1st Territorial Regiment of the Indian and Oklahoma Territories, and their participation in the Philippine Insurrection and guarding the Mexican border. The next call of duty for the 1st Oklahoma Regiment was WW I. Most of the Oklahoma 
 
Guard combined with the 36th Infantry Division, Texas National Guard, while some small units fought with the 90th (Texas-Oklahoma) Infantry Division. The story of Oklahoma’s participation in World War I is relayed though photographs, artifacts, and documents housed in three exhibit cases..