Three issues are discussed in the beginning of this paper: general trends of urban population growth among blacks since 1930, regional variations in growth and distribution from 1950 to 1970, and urban growth and metropolitanization. The remainder of the paper examines the growth of the black urban population by size of place from 1950 to 1970. Size is seen to be related to black growth and this view is held to be reasonable, as size, if anything else, makes a city visible especially to potential migrants. Most studies of urbanization do not focus on size of place but on that segment of population defined as either urban or metropolitan or they focus on urbanized area growth. After looking at overall growth by size of place for the South and the remainder of the nation, a major component of city growth, that of in-migration is discussed. Here the role of migration in the growth of cities by size is analyzed for the 1965-1970 portion of the 1970 decade. Migration analysis concentrates on patterns found in the South and non-South, and in addition, gives some attention to the selection of city size on the part of the city-bound migrant according to his region of origin. A summary section presents the overall trends found in the research, the research of others, and discusses implications for the future growth of black urban America. (Author/AM)