The summer racial disturbances which have recently become epidemic have focussed attention upon the United States' most important and perplexing domestic problem-rampant racial ghettoization of its major cities. The Negro ghettos are to a considerable degree a product of American housing policies of the post-World War II era. Ironically, they now stand as one of the greatest obstacles to achievement of the nation's goal of decent housing for all its citizens. These racial concentrations-which are also concentrations of the most deprived of all Americans in virtually every sense of the term-are of impressive size. Today the Negro populations of at least five major cities are estimated to exceed half a million. Negroes constitute close to two-thirds of all residents of Washington, D.C.; more than one-third of the citizens of Baltimore and New Orleans; over one-fourth of those residing in Philadelphia, Detroit, Cleveland, and St. Louis.' In all cases they are compressed into limited areas, while large sections of the same cities remain almost exclusively white. In some places like New York and Los Angeles, where the Negro proportions are somewhat smaller, other severely disadvantaged groups like Puerto Ricans and Mexican-Americans are similarly ghettoized in large numbers. The recent rate of growth of the urban ghettos can best be described as explosive. During the I950s alone the Negro population of New York increased by forty-six per cent; of Detroit by sixty per cent; of Los Angeles by ninety-six per cent; of Milwaukee by a staggering 187 per cent.2 Such rapid increase in a problem-ridden population, together with its compression into areas of the central cities which are most deficient in housing and other facilities and services, helps explain why every one of these cities has recently suffered destructive racial violence. Today, violence is only the most extreme and obvious symptom of the problems which the slum ghettos are causing the major cities and this nation. Washington, D.C., where ghettoization has proceeded farthest of any, affords some illustrative statistics3 In the twelve years between i954 and I966, Washington's total population