Skyscraper

Skyscraper, extremely tall building. In the mid-19th century the rising cost of land in big cities made building upward rather than outward worthwhile, and this became practicable with the development of safe electric elevators. The first skyscraper was the 130-ft (39.6 m) Equitable Life Assurance Society Building in New York (1870). A major design breakthrough was the use of a load-bearing skeletal iron frame, first used in the 10-story Home Insurance Building in Chicago (1883). The tallest skyscrapers are the Sears Tower in Chicago and the World Trade Center in New York City, with more than 110 stories.