After unsuccessful attempts to secure federal funds, New York City Parks Commissioner Robert Moses proposed a Brooklyn–Battery Bridge.

Construction on the Brooklyn–Battery Tunnel started on October 28, 1940, but its completion was delayed due to World War II-related material shortages.

They pass underneath the East River, connecting the Battery at the southern tip of Manhattan to the neighborhood of Red Hook in Brooklyn.

[18][19] The Governors Island ventilation structure, designed by McKim, Mead & White,[20] is an octagonal building located over the midpoint of the tunnel's route, at its lowest point.

[33] In February 1930, the city publicized plans for a six-lane vehicular tunnel from West Street, Manhattan, to Hamilton Avenue, Brooklyn.

[36] Real-estate speculators believed that land prices along Hamilton Avenue would appreciate as a result of the tunnel's construction and that freight shipments could be delivered to Manhattan faster.

[35] In May 1930, the Terminal Bridge Corporation petitioned the New York City Board of Estimate for permission to build and operate a tunnel under the East River.

[42] Mayor Fiorello La Guardia set up a public-works authority in February 1935 so the city could apply for loans from the federal Public Works Administration (PWA).

[44] The same month, city officials hired temporary workers to survey sites for the proposed tunnel so that they could create a report for the PWA application.

[51] One civic group wanted to plan for future traffic volumes, so it asked the city to conduct further studies of the Brooklyn–Manhattan tunnel project.

[59] Although preliminary borings were set to start in February 1937, USACE officers on Governors Island opposed the placement of a ventilation tunnel there.

[75] Moses was able to garner support for the bridge from influential city and state politicians, including four of five borough presidents, Mayor La Guardia, and US Senator Robert F.

[78] The bill was proposed for a vote in the City Council, but this was blocked due to concerns that the bridge's connection to the East River Drive would not be able to accommodate future traffic volumes.

[79] The American Institute of Architects asked that the city reconsider the bridge, as it would obstruct the dramatic view of the Manhattan skyline, reduce the Battery to minuscule size, and destroy the Great New York Aquarium at Castle Clinton.

[82] La Guardia believed that if this revised plan were passed, Ickes would finally allocate a PWA grant to the bridge project.

[102] In October, in a last effort to garner official acceptance for the Battery Bridge plan, Moses and La Guardia appealed directly to President Roosevelt to form an independent committee to study the proposal.

Around this time, Roosevelt's administration was considering loosening PWA requirements and lowering interest rates so that the Battery Tunnel could qualify for these funds.

[107][108] After a meeting with La Guardia, RFC chair Jones announced that there were no obstacles to granting a $70-million (equivalent to $1.2 billion in 2023[26]) loan toward the tunnel project.

[118] On the Manhattan side, a large part of Little Syria, a mostly Christian Syrian/Lebanese neighborhood centered around Washington Street, was razed to create the entrance ramps for the tunnel.

[132] Another issue arose when it was revealed that the Great New York Aquarium at Castle Clinton, at the Battery on the Manhattan side, would need to be demolished to make way for the tunnel.

The parkway also included a bridge over the Gowanus Canal, a fixed span rising 90 feet (27 m) above the waterway before descending to Hicks Street.

[154][155] A contest for designing the Governors Island ventilation building was also held, and the contract was ultimately given to the architectural firm McKim, Mead & White.

[122] La Guardia had promised that, during World War II, the Brooklyn–Battery Tunnel would be given priority status over other construction projects due to its importance to the Brooklyn economy.

[161] Due to opposition over potentially firing the sandhogs, they were allowed to continue working until a final review of the WPB's action was conducted.

[36] By September 1944, the war was winding down and Mayor La Guardia was petitioning the US government to allow the manufacture of washers, nuts, and screws for the Brooklyn–Battery Tunnel construction effort.

[186] A reporter for the Brooklyn Eagle made an unsanctioned drive between the two ends of the tunnel, noting that tiles, lighting, and a road surface had yet to be added, although the bores themselves were complete.

The Brooklyn–Battery Tunnel was closed completely after the September 11 attacks due to the proximity of the Manhattan portal to the World Trade Center site.

[214][215] The Hugh L. Carey Tunnel reopened on November 13[216][217] following a cleanup process that included the removal of an estimated 86 million US gallons (330×10^6 L; 72×10^6 imp gal) of water.

[256][257] Drivers who use the tunnel and then remain on the FDR Drive or West Side Highway south of 60th Street would be exempt from the congestion toll.

[270] This was ultimately dropped from the final plan due to a state law that prohibited the conversion of the Henry Hudson Parkway to an Interstate Highway.