Baltimore/Washington International Thurgood Marshall Airport

During WWII, planning had already begun on a new airport to serve the Baltimore/Washington area. In 1944, the Baltimore Aviation Commission announced that a location had been found near Linthicum Heights, whereby a new airport could be built on 2,100 acres at the cost of $9 million. The State Aviation Commission approved the site in 1946, as it was a 15-minute drive from downtown Baltimore and was near the Pennsylvania Railroad line and the Baltimore and Annapolis Railroad line, as well as to the proposed Baltimore-Washington Parkway. Furthermore, visibility in the area was generally good. The ground was broken on March 2nd, 1947, on land purchased from the Friendship Methodist Church. The airport was dedicated Friendship International Airport on June 24th, 1950, by then-President Harry S. Truman. The total cost of construction ended up being $15 million. The following month airlines began arriving from the old Baltimore Municipal Airport, with Eastern Airlines flying the first flight into the airport on July 23rd, 1950. By 1957, the airline was being serviced by Eastern Airlines, Capital Airlines, American Airlines, National Airlines, TWA, United Airlines, Delta Air Lines, and Allegheny Airlines. Once jet service began, the airport was the only one in the area that could handle them at the time, so it became the airport for jets in May-June 1959 when American and TWA began flying transcontinental Boeing 707 jets. The Maryland Department of Transportation purchased Friendship International Airport from the City of Baltimore in 1972 (at the cost of $36 million). The Maryland State Aviation Administration took over operations at the airport and plans to upgrade and modernize all Maryland airports were promptly announced. Furthermore, airfield employees at the airport grew from 3 to over 200. In order to attract passengers from the Washington, D. C. area, the airport was renamed the Baltimore/Washington International Airport on November 16th, 1973 (although it took the IATA seven years for its new code to reflect the new name, as an airport had used BWI in Bewani, New Guinea). As for modernization, the first phase was completed in 1974 (at the cost of $30 million. This included improved landing capabilities and runway systems, three new air cargo terminals, and the expansion of the airport's freight capacity to 2.53 acres. By 1979 the terminal renovation work was complete, whereby the terminal had more than doubled in size (to 14.58 acres), with the number of gates increasing to 27 from 20 (at the cost of $70 million). Furthermore, the BWI Development Council was established to plan future airport development initiatives. In 1980, the BWI Rail Station was opened, thereby allowing Amtrak to provide a connection for passengers on the Northeast Corridor. It also provided access to Washington, D.C. Starting in the 1980s and continuing in the 90s, the airport was a hub for Piedmont Airlines and its successor U.S. Airways (which was forced to scale back in the wake of the dot com bust and the 9/11 attacks, as well as low-fare competition). The arrival of Southwest Airlines in 1993 allowed it to become the airport's largest carrier, with over 56% of passengers carried in 2011. In the early 90s Runway 15L/33R was extended by 1,800 feet to its current length of 5,000 feet, which allowed for the use of small passenger jets such as the Boeing 737. In 1997 the international terminal (Concourse E) was built, as the airport had seen international service from World Airlines (starting in 1981), followed by British Airways, Aer Lingus, Air Jamaica, Air Aruba, Air Greenland, El Al, Icelandair, KLM, Air Canada, Ladeco, and Mexicana, as well as military flights operated by the U.S. Air Force's Air Mobility Command. In July 2000, Ghana Airways began service to Accra, seeking to serve the many people of West African origin residing in the region (however, by July 2004, the airline was prohibited by the U.S. government from servicing the county, citing an expired license and the ignoring of orders to stop flying an unsafe plane). In 2006 North American Airlines introduced its own direct flight to Accra, which brought about the return of direct flights from BWI to Africa (although North American Airlines ended all scheduled service in May 2008). In 2005, Concourses A and B were renovated and expanded (and integrated with one another), in order to accommodate Southwest Airlines' ever-growing presence. This allowed the airline to house all its operations at the airport in one unified location. On October 1st of the same year, the airport was renamed the Baltimore/Washington International Thurgood Marshall Airport in honor of U.S. Supreme Court Justice Thurgood Marshall, who grew up in Baltimore. On August 5th, 2014, Runway 04/22 was permanently closed. The 6,000-foot runway had been scantily-used, essentially only when the main runways were in need of repairs. In late 2018 construction began on a five-gate expansion of Terminal A (on behalf of Southwest Airlines, at the cost of $60 million). The expansion went into service in 2021.

The airport is nine miles south of Downtown Baltimore and 30 miles northeast of Washington, D.C.

• The Friendship Methodist Church that initially stood on the land had to be razed, and 170 buried bodies had to be removed from the site. 
• BWI was the first US airport with an intercity rail station. 
• The airport has been a backdrop in several films, including Silence of the Lambs, Goldfinger, 12 Monkeys, Home for the Holidays, and more. 
• In 2008, Health magazine named BWI the second healthiest airport in the US. The following year the Airports Council International's survey of airport service quality had BWI ranked first in the world in the 15-to-25-million-passenger airport category.