In 1935 the Nazi-sympathizing German-American Bund established Camp Siegfried on Long Island. The land was owned by the German-American Settlement League, an organization which still operates as a private community.
http://www.longwood.k12.ny.us/history/yaphank/german_american_bund.htm
Yaphank
http://www.stonybrook.edu/lihj/IssueFiles/V21_2/Articles/Shaffer/shaffer.html