Despite the odds, African American women are achieving some success in science, technology, engineering, and mathematics (STEM). However, a dearth of empirical evidence exists on the mechanisms that contribute to their persistence. This study contributes to understanding how African American women are successful in obtaining baccalaureate degrees in the sciences. Specifically, through surveying students from multiple institutions of higher education, including Historically Black Colleges and Universities (HBCUs) and Predominately White Institutions (PWIs), the study examined how African American undergraduate women's self-efficacy, gender, race/ethnicity, department climate, and campus climate interact to promote career commitment. This project focused on a population at the crossroads of race and gender in STEM: African American women obtaining undergraduate degrees. Participants (N = 670) were African American (N = 375) and European American (N = 295) women and men enrolled in four universities in North Carolina (two PWIs, two HBCUs). Multiple regression analyses were used to examine the data. Results demonstrated that being a STEM major was the biggest predictor of career commitment across race and gender. For women with STEM majors, science/math self-efficacy emerged as the primary predictor of career commitment and perceptions of gender equality in one's major department were especially important for African American women. These results can be used to inform educational policy about training faculty members in classroom and campus climate issues. The results may also be useful to those designing interventions, to address issues of science/math self-efficacy of students who plan to pursue STEM careers after graduation. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]