_________ allowed for cities, such as Chicago, to grow upward, which transformed their skylines

Question

1. Steam power
2. Steel-cage construction
3. Growing immigrant populations
4. The Bessemer process

Answer 1

2. Steel-cage construction

Answer 2

Is that correct

Answer 3

Yes, that is correct. Steel-cage construction allowed for cities like Chicago to build taller buildings, transforming their skylines.