African American (AA) students graduate at significantly lower rates in science, technology, engineering, and mathematics (STEM) than their racial / ethnic counterparts. There are a number of factors that contribute to whether AA students ultimately decide to depart form their programs such as the pervasive science culture, academic preparedness, and the culture of the institution. To address the disparity in STEM degree completion, this dissertation examined variables that influence AA STEM persistence. The data for this study came from the Higher Education Research Institute at the University of California, Los Angeles. There were 379 first-time, full-time AA students in the study that attended predominantly white institutions. Additionally, three hypotheses guided this dissertation. First, students that engage with faculty mentors will have higher levels of STEM persistence. Next, AA students that demonstrate enhanced habits of mind will persist in their pursuit of STEM degrees. Finally, faculty diversity helps to create an inclusive educational environment which will have a positive influence on AA STEM persistence (McGee, 2016; Guiffrida, 2005; Weinberg, 2008). This dissertation used a quantitative method of analysis to investigate each research question from a post-positivist lens. Each regression analysis consisted of control variables that explored the extent of the relationship between the independent and dependent variables. The statistical tests revealed that there is a positive relationship between faculty mentor engagement and AA STEM persistence. However, the relationship between faculty mentor engagement and AA STEM persistence weakens to the point of non-significance when annual family income is entered into the equation. Next, that habits of mind are not a statistically significant predictor of AA STEM persistence; however, are positively correlated with faculty mentor engagement. Finally, faculty diversity has a positive correlation with AA STEM persistence. The findings of the statistical analysis revealed that faculty mentor engagement positively influences AA STEM persistence. Further, that habits of mind are not directly related to AA STEM persistence, yet indirectly influences faculty mentor engagement which is positively correlated to AA STEM persistence. Finally, that faculty diversity positively influences AA STEM persistence. This may be because AA students perceive the institution as more welcoming and inclusive when they have diverse faculty on campus (Umbach, 2006; Neville, & Parker, 2017). Based on the findings of this study, I recommend that postsecondary institutions help to create spaces on campus that focus on providing faulty with information on how to have meaningful mentor engagement with AA students in STEM, provide AA students in STEM with information related to habits of mind, and make a concerted effort to increase faculty diversity. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]