Skyscrapers background info

Modern skyscrapers are built with steel or reinforced concrete frameworks and curtain walls of glass or polished stone. Water pumps and elevators  where used as mechanical equipment during ancient times. In 1852 Elisha Otis introduced the safety elevator, allowing safe passenger movement to upper floors. The use of a steel frame instead of stone or brick, lead to an early development designed by Peter Ellis in 1864 which was the world's first iron-framed, glass curtain-walled office building, that was only 5 floors high. Most early skyscrapers developed in the areas of Chicago, London, and New York toward the end of the 19th century. Today modern skyscrapers are built with steel or reinforced concrete frameworks and curtain walls of glass or polished stone.

http://en.wikipedia.org/wiki/Skyscraper#History