A sharp residential separation of whites and blacks, documented statistically in research, could be observed in most American cities in the 1950s and 1960s. That separation, which could also be described as "segregation", was already under attack in the 1960s and 1970s by a variety of new federal policies emerging from all three branches of government. There were good reasons to believe in the mid-1970s that the pattern of residential concentration and isolation would erode. Thus further governmental interventions—whether to strengthen the prohibition of discrimination in rental, sales, and realtor behavior; to impose integration on new developments; or to integrate housing projects through public measures—were not necessary. Integration would happen in any case, as a result of economic, political, and social changes that were inevitable. The forces that will produce the changes people are looking for are individual and voluntaristic, rather than governmental and authoritative.