Please answer the following question: I know that the answer to the question "What group flooded into Philadelphia as part of the Great Migration?" is in "These immigrants were largely responsible for the first general strike in North America in 1835, in which workers in the city won the ten-hour workday. The city was a destination for thousands of Irish immigrants fleeing the Great Famine in the 1840s; housing for them was developed south of South Street, and was later occupied by succeeding immigrants. They established a network of Catholic churches and schools, and dominated the Catholic clergy for decades. Anti-Irish, anti-Catholic Nativist riots had erupted in Philadelphia in 1844. In the latter half of the century, immigrants from Russia, Eastern Europe and Italy; and African Americans from the southern U.S. settled in the city. Between 1880 and 1930, the African-American population of Philadelphia increased from 31,699 to 219,559. Twentieth-century black newcomers were part of the Great Migration out of the rural South to northern and midwestern industrial cities.". Can you tell me what it is?
Answer:
African Americans from the southern U.S