How did the influx of immigrants affect cities?

Question

A: The influx of immigrants led architects to develop new approaches to housing and transporting large numbers of people. This resulted in the development of skyscrapers, horsecars, cable cars, and electric trolley cars. Because congestion was so bad in the largest cities, engineers were also led to look for ways to move mass transit off the streets. Chicago responded by building an elevated railroad, while Boston, followed by New York, built America's first subway systems. Not all of the effects caused by the influx of immigrants were positive, however. Sanitation conditions of major cities became inadequate because cities were simply unable to keep up with the influx of immigrants. These cities also became overpopulated.

Answer 1

Much better. Good job.