Page "Great Migration (African American)" Paragraph 6

Between 1910 and 1930, the African-American population increased by about forty percent in Northern states as a result of the migration, mostly in the major cities.

Cities including Detroit, Chicago, Cleveland, and New York City had some of the biggest increases in the early part of the 20th century.

Blacks were recruited for industrial jobs, such as positions with the expansion of the Pennsylvania Railroad.

Because changes were concentrated in cities, which had also attracted millions of new or recent European immigrants, tensions rose as the people competed for jobs and housing.

Tensions were often most severe between ethnic Irish, defending their recently gained positions and territory, and recent immigrants and blacks.