The creation and perpetuation of the social spatial mosaic of a metropolitan area in the United States is a result of thousands of individual migrations. Each of these moves involved a decision-making process that included elements unique to each household. Embodied in each decision were personally unique goals, needs, and aspirations, as well as particular constraints that may have qualified or limited the realization of these desires. Virtually every household is subject to constraints. Income and distance to work, for example, are limitations that are experienced by most households. Households of a few subgroups, however, experience a unique set of constraints. Blacks, for example, have been limited to a particular segment of the city, primarily as a function of race. This limitation still exists, regardless of strong civil rights laws and activities that have occurred during the last decade. Blacks may be termed a constrained population, therefore, because of this unique and influential limitation. Intra-urban migration is a popular topic among the many geographers, sociologists, and other urbanists concerned with the social composition of the American City. The traditional