Moynihan Train Hall occupies part of the James A. Farley Building, a Beaux-Arts structure designed by McKim, Mead & White alongside the original Penn Station, and opened in 1914 as New York City's main post office.

[11][14][15] Part of the Moynihan Train Hall project is an expansion of the preexisting West End Concourse under the eastern side of the Farley Building.

[16] Located under the grand staircase of the post office, the concourse was widened to serve nine of Pennsylvania Station's 11 platforms, and new street entrances were opened from the southeast and northeast corners of the Farley Building.

[17][18] The concourse, which was constructed in 1994 as part of a renovation to the LIRR's section of Penn Station,[19] provides access to the seventeen tracks served by Moynihan Train Hall.

[22] Because of the layout of the platforms, Moynihan Train Hall serves 17 of Penn Station's 21 tracks, which are used by Long Island Rail Road (LIRR) and Amtrak.

The existing station house continues to provide alternate access to the LIRR and Amtrak, particularly at night, when Moynihan Train Hall is closed.

[27] In the early 1990s, U.S. senator Daniel Patrick Moynihan began championing a plan to rebuild a replica of the historic Penn Station, in which he had shined shoes during the Great Depression.

[30] At the time, existing facilities at Penn Station were overcrowded and the United States Postal Service (USPS) was planning to relocate much of its operations from the Farley Post Office.

[31] Hellmuth, Obata & Kassabaum (HOK)'s plan, which was made public in May 1993, called for a 120-foot parabolic arched roof, rising above a passenger concourse within the post office's old sorting room.

The corporation, led by a bipartisan group of New York state government officials, initially had $300,000, but raised $670 million within ten years.

[37] By that March, officials had formed an agreement in which the USPS would retain its operations in part of the Farley Building while giving over another portion to the new train hall.

[41][42] Childs's design would have involved demolishing the post office's sorting room floor and replacing it with a multilevel concourse that allowed views of the tracks.

[46] U.S. senator Charles Schumer had unsuccessfully sponsored a bill that May, which would have formally named the facility "Daniel Patrick Moynihan Station", in honor of his colleague who was retiring.

[48] In early 2001, the Staubach Company and Fraport were selected to develop the Farley train hall as a joint venture; the start of construction had been pushed back yet again to late 2001.

The Carpenter and HOK plan simplified the concourse into a single level and added numerous skylights, reminiscent of the original Penn Station.

[58][59] The Empire State Development Corporation selected Vornado Realty Trust and The Related Companies to operate the retail space.

[66] That September, after months of negotiations involving Senator Chuck Schumer, New York governor David Paterson, and PANYNJ Executive Director Christopher O.

[67][68] Some $169 million provided by federal and state sources was already in place[69] when a Transportation Investment Generating Economic Recovery (TIGER) Grant arrived in early 2010.

Phase 1 consisted of the two fully-designed elements of the plan: an extended underground West End Concourse for the Long Island Rail Road and two entrances to the existing Penn Station platforms through the Farley Building on Eighth Avenue.

[74][75][76] In May 2012, the Port Authority of New York and New Jersey (PANYNJ) announced that a $270 million contract for the first phase, including the concourse expansion under 8th Avenue, had been awarded.

However, the opening was delayed because the New York state government decided to upgrade digital information boards and other technology in the concourse just before it was completed.

[83] In January 2016, New York governor Cuomo announced plans for a combined Penn-Farley Post Office complex, a project estimated to cost $3 billion.

[11] State officials aimed to complete the project by the end of 2020, under the leadership of Moynihan Station Development Corporation president Michael Evans.

The state continued to push for a timely completion despite last-minute requests and budget issues, and the stresses of the project may have led Evans to kill himself in March 2020.

[102] On January 11, 2021, Cuomo announced a proposal to connect the High Line linear park, two blocks west, to the Moynihan Train Hall.

[108] In June 2022, Open House New York conferred its 2022 Open City Award to the Moynihan Train Hall Team, which includes primary client Empire State Development in a public-private partnership with Vornado Realty Trust, architect Skidmore, Owings & Merrill, WSP USA (construction management), Skanska USA (construction), Severud Associates (structural engineering), Jaros, Baum & Bolles (MEP/FP/IT/Telecom), Langan (civil/geotechnical engineering) and several other specialty designers and contractors.

[110][112] Officials have stated the lack of seating is designed for improving the "circulation" of people, but critics have argued it is hostile architecture to keep away the homeless.