Trends and projections for postsecondary enrollments in the United States are summarized. Between 1955 and 1970, degree credit enrollment more than tripled due to both a rapid rise in the population of college-age youth and an increase in the college participation rate. College attendance doubled between 1955 and 1965, and participation rates for women and blacks grew even faster. The larger part of the increase in students was accommodated by the growth of publicly-supported higher education. After the early 1970s, enrollment growth was slower, and 95 percent of the increase was due to the increased enrollment of women, many of nontraditional age. Although blacks made considerable strides, their participation rates were still lower than those of whites in 1979. It is projected that until the middle to late 1990s, the population of prime college-going ages, 18 to 24, and 25 to 34 years, will decline greatly as the children of the baby boom are replaced by the smaller cohorts born after 1965. These declines will be much greater in the Northeast and Northcentral states than in the South and West. Private education will probably be affected more by the declines than public education. Institutions that serve working adults will not experience demographically-caused decline until the late 1980s. (SW)