Which river separates Manhattan from New Jersey?

The Hudson River serves as the boundary between Manhattan and New Jersey, making it the correct choice. This river flows in a north-south direction and is historically significant, as it played a crucial role in the development of New York City and its surrounding regions. The waterfronts of both Manhattan and New Jersey are vibrant areas, with parks, piers, and recreational spaces that take advantage of the beautiful views across the river.

The East River, in contrast, does not separate Manhattan from New Jersey; instead, it runs along the eastern edge of Manhattan, separating it from Brooklyn and Queens. The Harlem River primarily connects the Hudson River to the East River and is situated to the north of Manhattan, separating it from the Bronx. The Gowanus Canal, a much smaller waterway located in Brooklyn, is not in proximity to the border between Manhattan and New Jersey and has a very different significance, primarily related to industrial history and local ecology. Understanding the geography of New York City's waterways is essential for any tour guide, as it provides context for the urban layout and historical development of the region.