The Empire State Building was completed in 1931.
Construction began on March 17, 1930, during the early years of the Great Depression. The project rose on the former site of the Waldorf-Astoria Hotel and was developed by Empire State Inc. Architects Shreve, Lamb & Harmon designed the skyscraper in the Art Deco style, while Starrett Brothers and Eken served as the main builders.
The building was structurally completed on April 11, 1931—just 410 days after construction began and ahead of schedule. New York governor and former presidential candidate Al Smith ceremonially drove in the final rivet. The official opening followed on May 1, 1931, when President Herbert Hoover switched on the building's lights from Washington, D.C.
A common mix-up is to confuse completion with opening: both events occurred in 1931, but the structure was finished in April and formally opened in May. At 1,454 feet including its antenna, it remained the world's tallest building until 1970.