Trylon and Perisphere were known as the "Theme Center." The Perisphere had a diameter of 180 feet and housed a diorama called "Democracity."
this 1939 New York World's Fair website, some of the exhibitors in the building were The Book House for Children, The Independent Order of Foresters, Keystone Manufacturing Company, Underwood & Underwood and Universal Camera Corporation.
Hall of Nations, which included Albania, Cuba, Iceland, Iraq, Yugoslavia, Siam, Haiti and many others. The only major world power that did not participate in this World's Fair was Germany.
Polish Building and Tower. The statue -- the King Jagiello Monument -- that can be seen on the left-hand side of the tower was a replica of one that was converted into bullets by the Germans after they invaded Warsaw. The monument now resides in Central Park. The Am-Pol Eagle has an interesting article about the 1939 World's Fair and Poland's place in it.