The influx of immigrants to the US in the late nineteenth century drastically increased the population of large cities, where many immigrants settled. This increase in population led to overcrowding, poor living conditions, disease, and a great deal of suffering.
Immigrants flocked to the US in the second half of the nineteenth century to escape poverty, overcrowding, and unemployment in their home countries. They longed for a better life, and many of them had stars in their eyes about America. They had visions of making a prosperous new home for themselves and their families, earning a lot of money, and perhaps buying land and a house of their own. Yet often, immigrants found themselves disillusioned shortly after their arrival, as their American dreams didn't turn out to be quite what they thought.
Immigrants that remained in large cities like New York City usually lived in areas of the city dedicated to their nationality or ethnic group. Conditions were overcrowded, and the several-story tenement houses were packed with people, often filthy, and typically unsafe. Disease ran rampant through these neighborhoods. Fire was a constant threat. Crime also became an issue as unscrupulous people preyed on immigrants.
As more and more working immigrants moved into large cities, factories grew up and expanded to provide jobs for them. Working conditions in these factories were horrendous. People were packed into noisy, dirty workshops, worked long hours, and earned only minimal pay. Safety measures were largely nonexistent, and disasters like the Triangle Shirtwaist Factory fire took many lives.
Indeed, cities expanded rapidly during this period as more and more immigrants moved in, and conditions were generally quite poor. Yet people survived, and some even thrived in their new homeland.