The Great Migration in U.S. history refers to the mass movement of African Americans from the rural South to urban centers in the North, occurring mainly between 1916 and 1970. This migration was driven by several factors, including the search for better economic opportunities, escape from Jim Crow laws and racial violence, and the promise of higher wages in industrial jobs during and after World War I. Major cities like Chicago, Detroit, and New York experienced significant demographic changes due to this influx, leading to vibrant African American cultural movements, such as the Harlem Renaissance, while also intensifying racial tensions and segregation in Northern cities.