By 1890 the United States had expanded from the Atlantic Ocean to the Pacific. With growing populations in the Great Plains and the West, the frontier was considered closed. But the nation was far from settled. The turn of the century would be a time of great movement from the farmlands to the cities of America owing to the jobs and demand for labor caused by industrialization. African Americans in the South were drawn to the cities of the North by the promise of work and improved circumstances. They also desired to escape from racism in the post–Civil War South, which had fought in favor of slavery and was bitter about losing the war and the right to own slaves. By 1915 they were heading to the industrial cities by the thousands, beginning the historic African American Great Migration.

All the migrations that occurred during the United States...