The terminal was built to handle Pan Am's fleet of flying boats, the Boeing 314 Clippers, which landed on the nearby Bowery Bay.

Technological advances after World War II made the Clippers obsolete, and the Marine Air Terminal was renovated in 1946 to serve conventional planes.

The three-story rectangular entrance pavilion contains a canopy and a set of doors leading to the terminal's main rotunda.

Both the interior and the exterior of the main building were designated as New York City landmarks in 1980, and the structure was added to the National Register of Historic Places in 1982.

[22] Covering 558 acres (226 ha) with nearly 4 miles (6.4 km) of runways, the airport cost $40 million, making it the largest and most expensive in the world at that time.

[23] At a hearing before the Civil Aeronautics Board in April 1939, Pan American Airways indicated that it planned to use North Beach Airport as the main U.S. terminal for the transatlantic flights of its Boeing 314 Clippers.

[36] In July 1940, American Export Airlines and city officials began discussing the possibility of constructing a second seaplane hangar next to the Marine Air Terminal.

American Export wanted to operate a transatlantic passenger route from LaGuardia Airport, but Pan Am did not have any more space in its existing hangar.

[36] A New York Herald Tribune article in 1942 noted that Clipper flights came from as far as "Capetown, Lisbon, New Zealand, the Orient, Alaska and other remote places".

[54] The Daily Boston Globe wrote that the rotunda often saw as much traffic as a subway station during rush hours, with up to ten overseas flights trying to land nearly simultaneously at the busiest times.

[60] That September, Port Authority officials suggested extending one of LaGuardia's runways by infilling an unused plot of land next to the International Air Terminal.

The New York Times described the terminal in 1960 as having "an air of decay and desolation", with a dirty skylight, broken equipment, peeling paint, and almost no passengers.

[80] After the Federal Aviation Administration banned non-scheduled airlines from operating regular flights and selling tickets in the 1960s, the Marine Air Terminal sat nearly empty for several years.

[83] That February, philanthropist Laurance Rockefeller and magazine publisher DeWitt Wallace agreed to partially fund the restoration of the Flight mural,[69][84] which was projected to cost $75,000.

[70] The LPC designated the main building's facade and a portion of its interior as landmarks in late 1980, citing it as "the only active terminal in the United States dating from the first generation of passenger air travel".

[93][94] Days before the renovations were to be completed, several politicians attempted to halt the project, claiming that the Port Authority had illegally modified the portion of the terminal that had been designated as a landmark.

[98][99] As a result, the shuttle was initially unable to compete with Eastern Air Lines, which carried the majority of passengers who flew between New York and Boston.

Architectural firm Beyer Blinder Belle was hired to restore the terminal building to its original design, including light fixtures, canopies, and signage, at a cost of $600,000.

[117] The Port Authority voted to install vehicular bollards in front of the terminal in 2007 due to security concerns following the September 11 attacks.

[125] In 2015, New York governor Andrew Cuomo and vice president Joe Biden announced a $4 billion plan to rebuild most of LaGuardia's terminals as one contiguous building.

[130] JetBlue used the Marine Air Terminal for flights to Boston, Orlando, Fort Lauderdale, and West Palm Beach.

[143] The terminal's main building is a circular two-story structure flanked by a pair of one-story wings facing northwest and northeast toward Bowery Bay.

[146][147] The entrance pavilion and the rear wings were all intended as access points into the central core, which housed the primary functions of the terminal.

[149] In addition, the second story is topped by a terracotta frieze, which depicts yellow flying fish against a background of light and dark blue waves.

The entrance, at the center of this pavilion, consists of a doorway with four stainless steel doors, which are topped by transom panels depicting a pair of winged globes.

[23] The main building's control tower contained radio equipment for monitoring seaplane landings and takeoffs in Bowery Bay.

The first section depicts early history of aviation, including prehistoric humans' inability to fly; the Greek myth of Icarus, who flew too close to the sun and got burned; and the flight-related inventions of Leonardo da Vinci.

[68] It is unknown why this was done; The Wall Street Journal said it may have been due to anti-communist sentiment, but LaGuardia operations chief Anthony Cycovek said the rotunda had begun to look dingy when the mural was painted over.

[34] In the late 1970s, Geoffrey Arend, an aviation historian and author of Great Airports: LaGuardia, mounted a campaign to restore the mural to its original splendor.

[23] After the Clippers stopped serving the Marine Air Terminal, the hangar was used to store maintenance vehicles, as well as for LaGuardia Airport's executive offices.