The competitive dynamics that sustain stratification among postsecondary institutions have reinforced racial inequality in selective college enrollment between 1972 and 2004. Using a data set constructed from four nationally representative surveys (National Longitudinal Survey 1972, High School & Beyond 1980, National Educational Longitudinal Survey 1988, and Educational Longitudinal Survey 2002), the authors model how escalating admissions standards--including academic preparation and the growing importance of SAT scores and extracurricular leadership--effectively maintain racial inequality in selective college enrollment over time. Black and Latino students have made strides in their pre-collegiate academic preparation. Nevertheless, although access to postsecondary education has expanded since 1972 for all ethnic groups, Black and Latino students' odds of selective college enrollment have declined relative to White and Asian American students. (Contains 7 figures, 4 tables and 6 notes.)