 The Unisphere was announced by Moses in February 1961, and a model of the proposed work was unveiled the following year.Initially conceptually designed by the landscape architect in aluminum with metallic mesh continents; it underwent a further refined industrial design in stainless steel by industrial designers at Peter Muller-Munk Associates, and with engineering and fabrication by American Bridge Company, a division of US Steel.The sphere was built within 110 days.