Dayton is the sixth largest city in the U.S. state of Ohio and the county seat of Montgomery County, Dayton is the fourth largest metropolitan area in Ohio and the 61st largest metropolitan area in the United States. The Dayton-Springfield-Greenville Combined Statistical Area had a population of 1,085,094 in 2000. Dayton is situated within the Miami Valley region of Ohio, just north of the Cincinnati metropolitan area.Dayton is within 500 mi (805 km) of 60% of the population and manufacturing capacity of the U.S. and so is defined as one of only two major logistics centroids in the United States. It plays host to significant industrial, aerospace, and technological/engineering research activity and is known for the many technical innovations and inventions developed there. Much of this innovation is due in part to Wright-Patterson Air Force Base and its place within the community. With the decline of heavy manufacturing, Dayton's businesses have diversified into a service economy, including the insurance and legal sectors and most importantly the healthcare and government sectors.Other than defense and aerospace, healthcare accounts for much of the Dayton area's economy. Hospitals in the Greater Dayton area have an estimated combined employment of nearly 32,000, a yearly economic impact of $6.8 billion. Many hospitals in the Dayton area are consistently ranked by Forbes, U.S. News & World Report, and HealthGrades for clinical excellence.Dayton is also noted for its association with aviation; the city is home to the National Museum of the United States Air Force. The city was the home of the signing of the Dayton Peace Accords, which brought an end to the war in Bosnia. Orville Wright, poet Paul Laurence Dunbar, and entrepreneur John H. Patterson were born in Dayton. Dayton is also known for its many patents, inventions, and inventors that have come from the area,