www.castlegarden.org was launched in 2005 to commemorate the 150th anniversary of Castle Garden as an immigration center.
What's a garden got to do with Scottish genealogy? Quite a lot actually.
Most people know about Ellis Island but what they don't know 90 odd% of the time is that Castle Garden was the precursor to it's more famous cousin.
(photograph - Castle Garden)
CG started life as a fort built to defend New York harbor from the British during the war of 1812. It was open to the public from 1824-1854(?) and saw use as a beer garden, restaurant, exhibit hall, theater and opera house. It became the immigrant processing/receiving center for the Port of New York from 1855-1890. (The local populace were not very happy about that turn of events.) From 1890-1892 immigrants were processed through the Old Barge Office.
Once Ellis Island opened up, Castle Garden became New York City's Aquarium 1896-1946. Like many areas of historic note it was scheduled for demolition but the public ranted and, while the building was saved, it lay empty for many years.
Now known as Castle Clinton National Monument it serves as the visitor center for New York's National Parks and Monuments at Battery Park.
The Daily Times published an interesting article about Castle Garden on August 4th 1855. http://theshipslist.com/pictures/castlegarden1855.htm
Ruth Coleman wrote an informative piece about the history of Castle Garden and other immigrant information http://www.genealogytoday.com/columns/ruby/011117.html
You can also find an interesting potted history at http://www.ancestry.com/learn/library/article.aspx?article=7233
Castle Garden is a free look-up site and I have been able to find a number of records (indexes) of family members who came from the motherland to the new one which then led me to other resources. The records are not complete due to a fire destroying some as they were being transferred to Ellis Island but it is still a valuable source and worth looking at.