Opening of NMAI with Elders on Mall, by , September 21, 2004, Smithsonian Archives - History Div, Group photograph of some of the chiefs and tribal elders attending the opening celebration of the Smithsonian's National Museum of the American Indian on the National Mall in Washington, D.C. Image was taken on the West Lawn of the U.S. Capitol at c. 3 pm. This event was the largest gathering of Native Americans in history..