ANSWER:
During the 19th century, an ever-increasing number of people started moving into America's urban areas, including a huge number of recently arrived settlers looking for a better life than the one they had abandoned.
EXPLANATION:
- In New York, where the population multiplied each decade from 1800 to 1880, buildings that had once been single-family residences were partitioned into different living spaces to accommodate this increasing crowd.
- Known as Tenements, these small, low-rise condo buildings, a large number of them located in the city's Lower East Side neighborhood were very frequently cramped, dark, and lacked proper ventilation and plumbing.
- The condition on these Tenements was very poor and needed reforming.
