<P> The skyscraper would become the hallmark of the downtown area . Prior to the invention of the elevator -- and later the high - speed elevator -- buildings were limited in height to about six stories , which was a de facto limit set by the amount of stairs it was assumed that people would climb , but with the elevator , that limit was shattered , and buildings began to be constructed up to about sixteen stories . What limited them then was the thickness of the masonry needed at the base to hold the weight of the building above it . As the buildings got taller , the thickness of the masonry and the space needed for elevators did not allow for sufficient rentable space to make the building profitable . What shattered that restriction was the invention of first the iron - and then the steel frame building , in which the building 's load was carried by an internal metal frame skeleton , which the masonry -- and later glass -- simply hung off of without carrying any weight . </P>
<P> The skyscraper would become the hallmark of the downtown area . Prior to the invention of the elevator -- and later the high - speed elevator -- buildings were limited in height to about six stories , which was a de facto limit set by the amount of stairs it was assumed that people would climb , but with the elevator , that limit was shattered , and buildings began to be constructed up to about sixteen stories . What limited them then was the thickness of the masonry needed at the base to hold the weight of the building above it . As the buildings got taller , the thickness of the masonry and the space needed for elevators did not allow for sufficient rentable space to make the building profitable . What shattered that restriction was the invention of first the iron - and then the steel frame building , in which the building 's load was carried by an internal metal frame skeleton , which the masonry -- and later glass -- simply hung off of without carrying any weight . </P>
the centers of most cities became business areas after the invention of what
the centers of most cities became business areas after the invention of what
skyscraper
skyscraper