Baltimore Municipal Airport ("Harbor Field") is a former airport and United States Air Force airfield about 6 miles southeast of Baltimore, Maryland on an artificial peninsula. Construction began in 1929 with a seaplane base and was completed in 1941. It closed on 30 December 1960. The western half of the airport was within the city of Baltimore, whereas the eastern half was in Dundalk, in Baltimore County.
Today the former airfield is the site of the Dundalk Marine Terminal, a multi-use shipping facility of the Port of Baltimore.
Construction of "Baltimore Municipal Airport" began in 1929 under authority and exertions of the municipal government of the City of Baltimore. The airport was planned as a replacement for the smaller Logan Field of the 1920s, which was next to the planned site of the new airport. It was built on an artificial peninsula built from dredged harbor silt alongside the old Colgate Creek on the "Patapsco Neck" peninsula (which ends and juts out into the Chesapeake Bay between the Patapsco River to the south and Back River (Maryland) in the north at Sparrows Point and North Point). Lower Colgate Creek flowed into the Patapsco River and is today the site of the Dundalk Marine Terminal facility of the Helen Delich Bentley Port of Baltimore.
A seaplane facility was opened by Pan American Airlines in 1932, and by 1937 Imperial Airlines began operation out of the airport (seaplane use subsequently declined, and by the end of the 1940s the seaplane facilities had fallen into disuse). Various airlines and "Pan Am" seaplanes (known as "Clippers") used the facility until World War II. Problems with the harbor silt led to lengthy delays and the facilities for land-based aircraft weren't ready for use until 1941.
Civil traffic was suspended in 1942, when the United States Army Air Corps took over the airfield. The Army Air Corps used "Baltimore Army Airfield" as a I Fighter Command training airfield. Units assigned to the airfield were the 324th Fighter Group (6 July-28 October 1942); 353rd Fighter Group (26 October 1942 – 27 May 1943), and the 358th Fighter Group (28 April-28 May 1943). Beginning in 1943, it was transferred to the Air Technical Service Command as a repair and maintenance sub-depot for the Middletown Air Depot, located near Harrisburg, Pennsylvania.