The Chicago School is a name given to a group of architects and designers working in Chicago around the turn of the century, including Daniel Burnham (1846–1912), William Le Baron Jenney (1832–1907), and Louis Sullivan (1856–1924). One of the greatest engineering innovations associated with the Chicago School is the development of the steel-framed skyscraper. The use of iron and steel allowed engineers to build ever-taller buildings, usually for commercial purposes. Some of the earliest skyscrapers include the Home Insurance Building (1884), and the ten-story Rand McNally Building, designed by Burnham and Root in 1889.