Iowa was admitted to the union as the 29th state on Dec. 28, 1846. As a Midwestern state, Iowa forms a bridge between the forests of the east and the grasslands of the high prairie plains to the west. Its gently rolling landscape rises slowly as it extends westward from the Mississippi River, which forms its entire eastern border. The Missouri River and its tributary, the Big Sioux, form the western border, making Iowa the only U.S. state that has two parallel rivers defining its borders. Iowa is bounded by the states of Minnesota to the north, Wisconsin and Illinois to the east, Missouri to the south, and Nebraska and South Dakota to the west. Des Moines, in the south-central part of the state, is the capital. The state name is derived from the Iowa Native American people who once inhabited the area.