The Battery Conservancy launched CastleGarden.org on August 1, 2005 to commemorate the 150th anniversary of the opening of the immigrant depot at Castle Garden on August 1, 1855. Ten million names are already included in the database, with 2 million more to be added over the next few months.
You can search by first and/or last name and a range of years directly from the Castle Garden site. Advanced search options are also available, but they require payment. If you'd like to narrow down your search by ship, town of origin, age at arrival, or other database feature, try this free One-Step Castle Garden Database Search by Steve Morse.