Woven throughout the history of the United States is a narrative of human movement. The story of this country, we argue, is a tale of the constant flow of people across geographic spaces—both voluntary and forced immigrations, migrations, and the settlements of villages, city neighborhoods, and suburban communities. Beginning with Native Americans' ancestors who traversed the Bering Straight, "movement" has been a central, identifying theme of this nation.

The flow of several waves of European immigrants onto colonial shores and across the plains and the haulage of millions of Africans via the slave trade redefined the United States demographically and geopolitically, as did the mass migration of freed African Americans from the South to the North and from the farms to the cities in the 20th century. The post- World War II construction of suburbia enabled the European immigrants and their decedents to migrate from the cities to the suburbs en masse, changing not only the character of suburbia but also the cities and ethnic enclaves they left behind. As if choreographed by the federal government, local zoning laws and real estate markets, this flow of whites to the suburbs was synchronized with the arrival of African American migrants into specific and highly contained city neighborhoods.

But even the resulting racially segregated pattern of "vanilla suburbs" and "chocolate cities" that seemed fairly stable by the late 1970s across most metro areas was subject to change. Beginning in the late 1960s, new waves of immigrants, primarily from Latin America and Asia, entered the urban neighborhoods abandoned by their European immigrant predecessors. By the 1980s, growing numbers of African Americans had begun migrating to the suburbs. And, in the last decade, more Latino and Asian immigrants have chosen suburban communities as their port of entry to the United States. At the same time, whites— particularly affluent and well-educated professionals—are migrating back into cosmopolitan and gentrified city neighborhoods, opting out of increasingly diverse suburbs.