and southern Europe of the late nineteenth and early twentieth centuries, and the Great Migration of African Americans from the South to the North. Since changes to immigration laws in the 1960s, there have been new ethnic successions with the arrival of immigrants from Mexico, Central and South America; Africa and Asia. In addition, industrial restructuring and major economic changes upended the economies of cities throughout the Rust Belt, with implications for ethnic succession. In addition, there has been increased population movement to the South and Southwest over recent decades, causing shifts in population and voting patterns across the country. St Louis, Chicago, Cleveland, and Detroit Ethnic succession has been studied in these four cities of the Midwest, which had dramatic growth in the late nineteenth and early twentieth centuries, fueled by industrialization, commodity resources, shipping traffic, and the automobile industry. From World War I through the 1930s, many African Americans moved to northern and midwestern cities in the first wave of the Great Migration. In addition, each of these cities received in total millions of immigrants from southern and eastern Europe. Both the new immigrants and blacks competed with contemporary working class groups for housing and jobs. In Chicago, for example, ethnic Irish had become well established since the immigration of the mid-nineteenth century, and its members violently defended the physical boundaries of its neighborhoods, and its control of local working-class jobs. Similar issues prevailed in St. Louis, but the major nineteenth-century immigration had been by Germans. In both cases, the earlier ethnic groups resisted and tried to dominate the later ones, leading to outbreaks of violence in some cases. Tensions fueled by labor competition and post-World War I social tensions caused race riots, with ethnic whites, especially of Irish descent, attacking blacks during the summer of 1919 in Chicago. East St. Louis had a similar riot in 1917 that erupted after a strike. White flight In the United States, ethnic succession has been seen both among Europeans groups and between European-American and other ethnic groups. By the late nineteenth century, some cities were served by commuter railroads and trolley public transportation, which made longer commutes to work easier. The wealthiest people were the first to move out to new suburban developments. Such new transportation systems stimulated residential real estate development in train and trolley suburbs, and people who could afford to move out of the inner cities started