Final answer:
Carnegie's Bessemer steel process and the invention of the elevator contributed to the creation of skyscrapers and the expansion of railroads, marking a new industrialized age.
Step-by-step explanation:
Andrew Carnegie's adoption of the Bessemer steel process and the invention of the elevator played a pivotal role in the creation of modern skyscrapers and the expansion of railroads. The Bessemer process, which made it possible to mass-produce strong and cheap steel, and the safe, reliable elevator, which allowed for the vertical transportation of people and goods, both contributed to a seismic shift in architecture and urban development. These innovations enabled buildings to rise to unprecedented heights, changed the landscapes of cities, spurred the growth of the steel and oil industries, and marked the beginning of a new industrialized age.