Sites in San Francisco (including the Presidio) and Marin County in California; St. Louis, Missouri; Boston, Massachusetts; Chicago, Illinois; Fairfield County, Connecticut; Westchester County and Flushing Meadows-Corona Park in New York; Tuskahoma, Oklahoma; the Black Hills of South Dakota; Belle Isle in Detroit, Michigan; and a site on Navy Island straddling the U.S.-Canada border were considered as potential sites for the UN Headquarters. San Francisco, where the UN was founded in 1945, was favored by Australia, New Zealand, China, and the Philippines due to the city's proximity to their countries. The UN and many of its delegates seriously considered Philadelphia for the headquarters; the city offered to donate land in several select sites, including Fairmount Park, Andorra, and a Center City location which would have placed the headquarters along a mall extending from Independence Hall to Penn's Landing. The Manhattan site was ultimately chosen over Philadelphia after John D. Rockefeller, Jr., offered to donate $8.5 million to purchase the land along the East River.; Robert Moses and Rockefeller Sr. convinced Nelson Rockefeller to buy the land after the Rockefellers' Kykuit estate in Mount Pleasant, New York was deemed too isolated from Manhattan.