The first skyscraper used a metal skeleton to stand 10 stories tall in 1884.

The Home Insurance Building in Chicago was 138 feet tall. It was the first building to use a metal frame to support its entire weight. This frame acted like a human skeleton. The walls were just a skin attached to the outside.Earlier buildings used masonry construction. This meant the bottom walls had to be very thick to support the floors above them. Some buildings had walls several feet thick at the base. This took up a lot of space and limited how high a building could go.Jenney used iron for the lower floors and steel for the upper floors. The steel came from the Carnegie-Phipps Steel Company. Steel is stronger than iron and can handle more pressure. This allowed the building to weigh only one-third as much as a stone building.Because the walls did not have to hold up the roof, architects could add more windows. This brought more natural light into the offices. The building was torn down in 1931. However, its design paved the way for much taller structures like the Empire State Building.