Wikipedia That Form Ever Follows Function and Sullivan

" Sullivan developed the shape of the tall steel skyscraper in late 19th Century Chicago at the very moment when technology, taste and economic forces converged violently and made it necessary to drop the established styles of the past. If the shape of the building was not going to be chosen out of the old pattern book something had to determine form, and according to Sullivan it was going to be the purpose of the building. It was "form follows function", as opposed to "form follows precedent". " (><)