The study of racial-ethnic minority and female undergraduates is especially important because their enrollment as a percentage of all undergraduates in institutions of higher education has grown steadily in recent years. Notably, women have surpassed men and now make up the majority of students enrolled in post-secondary institutions in the United States. This is an example of a rare reversal in a persistent form of gender inequality. However, few researchers have explored the intersection of race, class, and gender among students in post-secondary institutions. I address this gap in the literature by comparing black, white, Asian, and Hispanic male and female students' post-secondary achievement and attainment using the National Longitudinal Survey of Freshmen which compiles panel data on approximately 4,000 first-time freshmen entering twenty-eight selective colleges and universities in the U.S. in 1999 and graduating in 2003. The dissertation documents significant within-race differences by class and gender in academic performance and degree attainment. I also illustrate how students' diverse demographic and socioeconomic backgrounds, in conjunction with previous academic preparation and college major, are associated with and impact cumulative college grade point average. Finally, the dissertation assesses how background characteristics, campus friendships and experiences, and satisfaction with college influence the likelihood of graduation within four years of college entrance. My results indicate that within-race gender gaps in achievement and attainment are widest among black students. Black females earn higher cumulative college grade point averages and are more likely to graduate college in four years than black males. My results highlight the importance of mean high school grade point average, SAT scores, and Advanced Placement exams for cumulative college grade point average and suggest that white and Hispanic students and female students are benefiting more (than black and Asian students and male students) from the relationships between class status, cumulative college grade point average, and bachelor's degree attainment.