What was essential to the development of the modern skyscraper?

Question

Quizplus · Accepted Answer

The electric elevator allowed for buildings to be taller than before and made it easier for people to access the upper floors, thus making the development of the modern skyscraper possible. Pre-cut glass panes, truss-and-balloon framing, and cable cars may have contributed to the construction and aesthetics of skyscrapers, but they were not essential to their development.

What Was Essential to the Development of the Modern Skyscraper