An island of Upper New York Bay southwest of Manhattan. It was the chief immigration station of the United States from 1892 to 1943. Officially closed in 1954, the site was designated a National Monument in 1965, and the main building was opened to the public as a museum in 1990. a small island close to New York City, which for over 50 years (1892-1943) was the main centre for dealing with people arriving in the US who wanted to settle in the country as immigrants. Millions of people, mostly from Europe, passed through Ellis Island to become US citizens. Island, Upper New York Bay, southeastern New York, U.S. It lies southwest of Manhattan island and has an area of about 27 acres (11 hectares). In 1808 the state of New York sold the island to the federal government. It served as the nation's major immigration station from 1892 until 1943, when immigrant processing was moved to New York City proper. It became part of the Statue of Liberty National Monument in 1965; its restored main hall is the site of the Ellis Island Immigration Museum