The Midwestern United States (or Midwest) refers to the north-central states of the United States of America, specifically Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Ohio, Nebraska, North Dakota, South Dakota and Wisconsin. A 2006 Census Bureau estimate put the population at 66,217,736. Both the geographic center of the contiguous U.S. and the population center of the U.S. are in the Midwest. The United States Census Bureau divides this region into the East North Central States (essentially the Great Lakes States); and the West North Central States (essentially the Great Plains States).
The term Midwest has been in common use for over 100 years. Other designations for the region have fallen into disuse, such as the "Northwest" or "Old Northwest" (from Northwest Territory), "Mid-America," or "Heartland". Since the book Middletown appeared in 1929, sociologists have often used Midwestern cities, and the Midwest generally, as "typical" of the entire nation. The Midwest region of the United States has a higher employment to population ratio (the percentage of persons at least 16 years old employed) than the Northeast, the West, the South, or the Sun Belt states.