The agriculture industry is rivaled only by aviation as the most important creator of jobs in Kansas. Agribusiness and food production are responsible for about 1 out of every 5 Kansas jobs; Kansas has long been a leading U.S. producer of wheat and beef. Wichita, the state’s most populous city, is known as the Air Capital of the World. Cessna, Boeing, Raytheon and Bombardier all have operations in Wichita. Spirit AeroSystems and Cessna are the two largest providers of Wichita jobs. The healthcare industry is another major employer in Wichita. Koch Industries, the largest privately owned company in the world by revenue, is headquartered in Wichita. Koch is involved in petroleum, chemicals, commodities trading and many other fields. Overland Park, the second largest city in Kansas, has one of the most highly educated populations in the United States. Sprint Nextel Corporation and global engineering firm Black & Veatch are two of the largest single providers of jobs in Overland Park, Kansas. Though Kansas City is sometimes mistaken for being the largest city in Kansas, most of its population is on the Missouri side of the border. Sprint Nextel Corporation, the federal government and the U of KS Medical Center are some of the top sources of Kansas City, Kansas jobs.