New York City

New York City is the largest city in the United States by far, with about 8.5 million people in the five boroughs and some 19 million across its metropolitan region. It grew up around one of the world's great natural harbors, where the Hudson River meets the Atlantic through the Narrows, sheltered and deep enough for the biggest ships. That harbor, paired with the Erie Canal's route to the interior, made New York the nation's commercial gateway and largest port.

The city is built on islands and water. Manhattan and Staten Island are islands, Brooklyn and Queens sit on the western end of Long Island, and only the Bronx is on the mainland. The East River and Hudson, both tidal straits rather than true rivers, wrap Manhattan, whose hard bedrock — schist close to the surface — let builders anchor the skyscrapers that define its skyline. Bridges and tunnels stitch the pieces together.

That dense, vertical geography makes New York unlike anywhere else in America: the most populous and crowded city in the country, a global capital of finance, media, art, and immigration packed onto a handful of islands at the mouth of the Hudson. Its harbor still ranks among the busiest in the nation.