Indiana is a U.S. state located in the midwestern and Great Lakes regions of North America. Indiana is the 38th largest by area and the 16th most populous of the 50 United States. Indiana is the least extensive state in the contiguous United States west of the Appalachian Mountains. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th U.S. state on December 11, 1816.