What two technological innovations contributed to construction of skyscrapers?

Two key technological innovations that contributed to the construction of skyscrapers are the development of steel frame construction and the invention of the elevator. The steel frame allowed buildings to rise higher than traditional masonry structures by providing a strong, lightweight skeleton, while the elevator made it feasible to access upper floors efficiently, overcoming the limitations of height. Together, these innovations revolutionized urban architecture and enabled the vertical expansion of cities.