Chicago O'Hare International Airport , sometimes referred to as Chicago O'Hare, or simply O'Hare, is the main international airport serving Chicago, Illinois, located on the city's Northwest Side, approximately northwest of the Loop business district. Operated by the Chicago Department of Aviation and covering , O'Hare has non-stop flights to 214 destinations in North America, South America, the Caribbean, Europe, Africa, Asia, the Middle East, Oceania, and the North Atlantic region as of November 2022. As of 2022, O'Hare is considered the world's most connected airport. Designed to be the successor to Chicago's Midway International Airport, itself nicknamed the "busiest square mile in the world," O'Hare began as an airfield serving a Douglas manufacturing plant for C-54 military transports during World War II. It was renamed Orchard Field Airport in the mid-1940s and assigned the IATA code ORD. In 1949, it was renamed after aviator Edward "Butch" O'Hare, the U.S. Navy's first Medal of Honor recipient during that war. As the first major airport planned after World War II, O'Hare's innovative design pioneered concepts such as concourses, direct highway access to the terminal, jet bridges, and underground refueling systems. O'Hare became famous during the jet age, holding the distinction as the world's busiest airport from 1963 to 1998; today, it is the world's fourth-busiest airport for passenger counts, serving 54 million passengers in 2021. In 2019, O'Hare had 919,704 aircraft movements, averaging 2,520 per day, the most of any airport in the world in part because of a large number of regional flights. On the ground, road access to the airport is offered by airport shuttle, bus, or taxis by Interstate 190 (Kennedy Expressway), which goes directly into the airport. O'Hare serves as a major hub for both United Airlines (which is headquartered in Willis Tower) and American Airlines. It is also a focus city for Spirit Airlines. History Establishment and defense efforts Soon after the opening of Chicago Municipal Airport in 1926, the City of Chicago realized more airport capacity would be needed. The city government investigated various sites in the 1930s but made little progress before America's entry into World War II. O'Hare began as a manufacturing plant for Douglas C-54 Skymasters during World War II. The site was known as Orchard Place, previously a small German-American farming community. The plant, in the northeast corner of what is now the airport, needed easy access to the workforce of