The main cause of the Great Northern Migration, which occurred from the 1910s to the 1970s, was the search for better economic opportunities and escape from racial segregation and violence in the southern United States. African Americans sought to flee the oppressive conditions of Jim Crow laws and systemic racism, seeking work in northern industrial cities like Chicago, Detroit, and New York. This mass movement resulted in significant demographic changes and helped to establish vibrant black urban communities. It also laid the groundwork for pivotal cultural movements, including the Harlem Renaissance, and had lasting impacts on American society and politics.