A review of the literature on residential segregation reveals that Blacks remain the most segregated group in American cities, despite the more recent arrival of Hispanic and Asian groups. By one measure--the index of dissimilarity with respect to Whites--Blacks are 1.6 times more segregated than Hispanics, and twice as segregated as Asians. Race is a far stronger correlate of residential segregation than cultural or ethnic differences. The segregation of blacks showed little improvement--and perhaps worsened--during the 1960s, despite heightened awareness and activity from civil rights activity. Substantial improvement during the 1970s offset this deterioration and left the nation's cities marginally less segregated in 1980 than in 1960. Researchers express conflicting opinions on the importance of black suburbanization in reducing measurable segregation. In general, large, slow-growing cities with large existing minority populations exhibit the most segregated residential patterns. The North Central region of the country consistently shows the highest levels of segregation and the least encouraging signs of improvement. Implications for future research are discussed. Data are presented on four tables and figures. A list of 39 references is included. (BJV)