Due to artificial expansion, Ellis Island is within the boundaries of New York City and Jersey City, New Jersey, and therefore is within both the states of New Jersey and New York. It is wholly in the possession of the Federal government as a part of Statue of Liberty National Monument, however, and is under the jurisdiction of the US National Park Service.
The federal immigration station opened on January 1, 1892 and was closed in November 1954, but not before processing 12 million European immigrants (estimates range up to 20 million).
Today Ellis Island houses a museum reachable by ferry from Liberty State Park in Jersey City, New Jersey and from the southern tip of Manhattan in New York City. The Statue of Liberty, sometimes thought to be on Ellis Island because of its symbolism as a welcome to immigrants, is actually on nearby Liberty Island, which is about 1/2 mile to the South.
Ellis island was also known as "The Isle of Tears" or "Heartbreak Island." Some immigrants were sent back to their countries and did not become U.S. citizens after the long trip to Ellis Island.