Why was the invention of the elevator significant? A. It was the first time steel cables were used in construction.

B. It was Thomas Edison's most important invention.

C. It allowed for buildings to be built taller because people would not need to climb flights of stairs.

D. It led to Andrew Carnegie building a steel empire.

Which effect did the united states supreme court's decision in plessy v. ferguson have? 1. ending segregation in all public schools in america 2. protecting voting rights for african americans by eliminating literacy tests 3. upholding the rights of all citizens to be treated equally by the government 4. authorizing the system that kept black and white people separated