Black-white residential segregation persists in urban America. However, evidence from the 1990 Census suggests that peak segregation levels were reached in the past. This paper evaluates 1990 patterns and 1980- 90 trends in black-white segregation for the 232 U.S. metropolitan areas with substantial black populations. The authors review the historical forces which intensified segregation for much of the 20th century and identify key post-1960 developments which challenged institutionalized segregation. The results suggest the modest declines in segregation observed during the 1970s continued through the 1980s. While most metropolitan areas continued some declines in segregation, the magnitude of these changes were uneven, but most pronounced in particular kinds of areas. Testing hypotheses developed from an ecological model, the authors find that lowest 1990 segregation levels and greatest 1980-90 declines occurred in younger, southern and western metropolitan areas with significant recent housing construction. Because the black population continues to migrate into such areas, the authors speculate that black-white residential segregation will decline further -- though to levels well above those for Hispanics or Asians.