On May 1, 1931, President Herbert Hoover pushed a button in the White House in Washington, DC, which turned on the lights of the Empire State Building, thus officially opening the world's tallest building.
From 1931 to 1972, the Empire State Building was the tallest building in New York City. Located at 34th Street and Fifth Avenue, it stands 102 stories, or 1454 feet tall. It was designed by William Frederick Lamb and cost $40 million to build.
Ever since 9/11, the Empire State Building has once again been the tallest building in New York City, although it is no longer the tallest building in the world. Within a few years, however, if all goes according to the plan, the Freedom Tower will supplant the Empire State Building as the tallest building in New York City.
To commemorate the 75th anniversary, for the last few days the tower lights were kept dark to represent the NYC skyline before the building was opened. Starting today for a full week the tower lights will be all white, as they were back in 1931.
For more information, see Empire State Building: Official Internet Site