The author proposes that residential segregation is presently one of the greatest national problems. Suburban "white nooses" surround the cities, in which are concentrated the swelling nonwhite population. Former Federal mortgage policies gave preference to "modal" families--young, upwardly mobile couples with children, and thus excluded low-income families. Urban public housing fostered Negro dominance in cities as whites moved away, while urban renewal tended to create while white middle- and upper-middle enclaves. "Blockbusting," a prime example of private discrimination for profit, contributed to segregation patterns. The "new towns," self-contained urban complexes, in many ways also may perpetuate segregation. However, there are forces for change--nondiscriminatory Federal regulations, state and local fair housing laws, privately developed interracial communities, grass roots efforts to stabilize changing neighborhoods, and suburban fair housing groups. The needed massive National measures to end segregation would require comprehensive Federal planning and incentives, new types of subsidies to low income groups, higher minority incomes, and vigorous enforcement of anti-discrimination and equal opportunity laws. (NH)