In June 1928, Pan American Airways acquired 116 acres of land on NW 36th Street for the purpose of building a privately owned and operated international airport in Miami, Florida. The establishment of a commercial airport and of regularly scheduled international passenger airline service by Pan Am was a transformative event for the City of Miami. By September 1928, Pan Am had begun to operate regularly scheduled Air Mail service between Miami and Havana. On January 9, 1929, Pan American Airport, also known as Pan American Field, was officially dedicated at a ceremony that included the inauguration of a newly expanded route system to Nassau, Santiago (Cuba), Haiti, the Dominican Republic and San Juan, Puerto Rico. The ceremony was attended by thousands of residents, government officials, and aviation celebrities, who saw in the new airport the promise of a bright new future in international aviation for Miami. It was the first mainland airport in the United States to have international port of entry facilities. The passenger terminal building, designed by Delano & Aldrich of New York City, was the most advanced and luxurious in the country. Three hangars, two on the east and one on the west, provided housing and maintenance facilities for Pan Am's fleet of Sikorsky amphibian and Fokker aircraft. During the first two years of its operation, it was from this busy airport that Pan American Airways pioneered U.S. international passenger aviation. By the end of 1930, for the first time in history, Pan Am had succeeded in establishing regularly scheduled Air Mail and passenger airline service from the U.S. to the West Indies, Caribbean, and Central and South America. On April 1, 1930, a collaboration between Pan American and Eastern Air Transport (later to become known as Eastern Air Lines) was begun after Pan American Airport at NW 36th Street was designated as the first international field Post Office in the country. The announcement followed almost a year’s worth of efforts by the U.S. postal service to effect greater efficiencies in U.S. Air Mail delivery by coordinating the schedules of airlines involved in operating international and domestic Air Mail routes with railway connections to cities not served by airports. On January 1, 1931, Eastern Air Transport inaugurated regularly scheduled passenger service from Miami to New York from Pan Am’s NW 36th Street Airport. It was another historic event, a collaboration between the two airlines that made Miami the clearing point for a coordinated airline passenger system that extended from as far north as Canada to the tip of South America. No other U.S. city could boast such a distinction. Eastern Air Lines officially took up primary residence at the 36th Street Airport in August 1935. In 1940, Intercontinent Corporation, owned by William Pawley, built an aircraft manufacturing plant on land acquired immediately east of Pan American Field. The City and County, eager to encourage the growth of an aircraft manufacturing industry in Miami, agreed to finance and build runways and ground facilities at the Intercontinent plant, including an east–west runway that extended from Le Jeune Road as far west as Pan American Field, where it intersected with Pan Am's east–west runway. National Airlines, which had been operating in Miami at Miami's city-owned Municipal Airport since 1937, moved to the 36th Street Airport in 1942. National built a combined maintenance and terminal facility on LeJeune Road, across the street from the airport and would stop traffic on the road in order to taxi aircraft to and from its terminal. Miami Army Airfield opened in 1943 on 1400 acres of land acquired during World War II to the south of Pan American Field. The two airfields were listed in some directories as a single facility. Following World War II, the Dade County Port Authority embarked on a long-planned airport expansion in order to meet Miami's increasing commercial aviation needs.