An estimated 40 million people in the United States claim Irish ancestry. In the 19th century, the principle entry port was New York where immigrants embarked at the quarantine station on Staten Island before making their way onto mainland Manhatten. From 1855-1892 most arrived at the Castle Garden Immigration Centre and later (1892-1924) they first stood on American soil at the Ellis Island Immigration Centre. Smaller numbers also arrived at other ports, and many crossed the border from Canada (see Canada). We have traced many of our North American clients' ancestors on passenger lists, border crossings and on United States Federal and State Census records.