When reading up on the United Nations on Wikipedia, I noticed that Navy Island near Niagara falls was being considered at the time of the groups creation for it's location. I'm wondering what locations were considered outside of Manhattan, how seriously they were considered, and why New York was eventually chosen over them?
On 10 December 1945, the Congress of the United States unanimously resolved to invite the United Nations to establish its permanent home in that country. Thereafter, the decision to locate the United Nations near New York City was made by the General Assembly at its first session, held in London on 14 February 1946.
During the latter half of 1946, following selection of the United States as host country, a special United Nations site committee studied possible locations in such places as Philadelphia, Boston and San Francisco. While consideration was given at first to areas north of New York City, crowded Manhattan had not been seriously investigated. A last-minute offer of $8.5 million by John D. Rockefeller, Jr., for the purchase of the present site was accepted by a large majority of the General Assembly on 14 December 1946. New York City completed the site parcel by additional gifts of property.
The site chosen by the United Nations was a run-down area of slaughterhouses, light industry and a railroad barge landing.
Information taken from the United Nations Visitors Centre.
what locations were considered outside of Manhattan
More than 200 locations in the USA were proposed.
But first there was a choice of continent and country
"When a vote on the location of the headquarters was taken in London in 1945, the United Kingdom, France, the Netherlands, and Canada voted for a European headquarters."
Most UN members voted to locate the HQ in the USA
locations throughout the United States mounting bids to become the “capital of the world”. San Francisco and Philadelphia were frontrunners for a while. Detroit put in a surprisingly strong showing. Even Black Hills, South Dakota mounted a bid. New York City, and Manhattan in particular, (Robert Moses badly wanted it in Flushing) was something of a last minute compromise solution after all other sites had been rejected.
A whole book has been written on this subject. "Capital of the World: The Race to Host the United Nations", by Charlene Mires.
From 1944 to 1946, as the world pivoted from the Second World War to an unsteady peace, Americans in more than two hundred cities and towns mobilized to chase an implausible dream. The newly-created United Nations needed a meeting place, a central place for global diplomacy—a Capital of the World. But what would it look like, and where would it be? Without invitation, civic boosters in every region of the United States leapt at the prospect of transforming their hometowns into the Capital of the World. The idea stirred in big cities—Chicago, San Francisco, St. Louis, New Orleans, Denver, and more. It fired imaginations in the Black Hills of South Dakota and in small towns from coast to coast.