Several technological advances had to occur before the marvel of engineering in the Empire State Building (or skyscrapers of any sort) could be built. The elevator, obviously, was one. Lighter construction materials were another — buildings were often limited in the height by their weight; taller ones required huge bases to support them. By the 1930s both were in common use in 1,000-foot buildings around the city. All that was needed was the impetus for the building, like a (possibly apocryphal) bet between Walter Chrysler of the Chrysler Corporation and John Jakob Raskob of General Motors, as to who could build the tallest building.

On this day, May 1, 1933, back in Washington D.C. President Hoover pressed the button, and with that officially opened New York’s 102-story Empire State Building, the world’s tallest, eclipsing the recently built 1,046-foot Chrysler Building. Just to make sure it would be the tallest, the 1,250-foot tall structure added to the roof a lightning rod, for a grand total of 1,454 feet.

At the peak of construction, almost 3,400 workers were engaged in making some part of the building, Thanks to prefabricated materials and the steel framework design, it rose up at an average rate of 4½ stories per day. Working on its heights was a group of Mohawk Indians, known as “skywalkers,” who were documented in photographs casually riveting, welding, and enjoying lunch over dizzying height above the skyline.