How did immigration alter the nation's population and shape its politics?
During the 1800s, immigration mainly stemmed from Germany and Ireland, particularly after Europe struggled through a series of political and economic shocks and Ireland faced a potato famine in the 1840s. Nineteenth-century immigrants were largely Catholic, and they settled at first in cities. The Irish mainly settled in Northeastern cities, such as Boston and New York, while Germans also settled in these cities and in Midwestern cities such as Milwaukee and St. Louis.
Immigrant groups tended to vote for Democrats because the Democratic Party was the party of the working person, and immigrants tended to work either building railroads, laboring in factories, or building canals, among other jobs. The Republican Party, on the other hand, became the party of the elite and was associated with Protestants, while Catholics (and later, Jews) often voted for Democrats. Some Republicans were nativists—that is, they favored anti-immigration policies—while Democratic political machines such as Tammany Hall in New York courted immigrant votes and often won their votes by doling out favors. In the late 1800s and early 1900s, immigrants arrived in the United States from eastern and southern Europe. These people included Italians, Jews, Greeks, Poles, and others. These groups also often tended to favor urban areas and to vote Democratic.