The Holland Tunnel opened, connecting Manhattan with Jersey City under the Hudson River.

The Holland Tunnel is a vehicular tunnel under the Hudson River that connects Hudson Square and Lower Manhattan in New York City in the east to Jersey City, New Jersey, in the west. The tunnel is operated by the Port Authority of New York and New Jersey and carries Interstate 78. The New Jersey side of the tunnel is the eastern terminus of New Jersey Route 139. The Holland Tunnel is one of three vehicular crossings between Manhattan and New Jersey; the two others are the Lincoln Tunnel and George Washington Bridge.

Manhattan is the most densely populated and geographically smallest of the five boroughs of New York City. Coextensive with New York County, Manhattan is the smallest county by area in the U.S. state of New York. Located almost entirely on Manhattan Island near the southern tip of the state, Manhattan constitutes the center of the Northeast megalopolis and the urban core of the New York metropolitan area. Manhattan serves as New York City's economic and administrative center and has been described as the cultural, financial, media, and entertainment capital of the world.

Jersey City is the second-most populous city in the U.S. state of New Jersey, after Newark. It is the county seat of Hudson County and is the county's most populous city and its largest by area. As of the 2020 United States census, the city's population was 292,449, an increase of 44,852 (+18.1%) from the 2010 census count of 247,597, in turn an increase of 7,542 (+3.1%) from the 240,055 enumerated at the 2000 census. The Population Estimates Program calculated a population of 302,284 for 2024, making it the 70th-most populous municipality in the nation. With more than 40 languages spoken in more than 52% of homes and as of 2020, 42.5% of residents born outside the United States, it is the most ethnically diverse city in the United States.