Graduate education holds the potential to provide individuals with economically viable career opportunities. However, females, first-generation college students, and underrepresented minorities often face obstacles that can undermine their progress in graduate programs. Despite their lower enrollment and higher attrition rates, little is known about how best to support these underrepresented students in graduate education. This dissertation study used a concurrent, mixed methods design to investigate the supports and barriers graduate students experience during graduate school. In the qualitative study, a narrative analysis was conducted from interviews of graduate students who attended an R1 university in the southeastern United States. Fourteen interview transcripts were restoried into narratives, and nine major themes were identified through a typographic analysis: mentor support, sense of belonging, financial support, peer support, community, imposter phenomenon, microaggressions, family obligations, and access and opportunity (for academic research and writing). Short storylines were developed for the rhetorical analysis, which were used to derive opposition statements and syllogisms (logical arguments). Students were grouped based on salient characteristics in their stories to understand how the themes varied across the stories, including: first-generation students, part-time students, international students, students who left their Ph.D. programs, mental health concerns, research-focused, and community of support. The themes were organized into areas of emotional and academic support based on the analyses. Microaggressions, family obligations, and imposter phenomenon acted as academic and emotional inhibitors, or negative supports, for students. In contrast, mentor and peer supports provided both emotional and academic support. Financial support and access and opportunity functioned primarily as academic supports for the students, whereas sense of belonging and community were sources of emotional support. In the quantitative stage, the Graduate Student Success Survey (GSSS), previously validated by the author, was modified (GSSS-II) and broadly distributed to a national population of students. Exploratory and confirmatory factor analyses were used to test the validity and reliability of the revised survey, with 648 responses from 23 universities. A 7-factor, 40-item model was determined with the following subscales: mentor support, imposter phenomenon, financial support, microaggressions (race and gender), access and opportunity, persistence, and peer support. The survey results explained 52% of the data, and survey's factors had Cronbach's alpha ranging from 0.76-0.91, with an overall alpha of 0.88. Item analysis revealed significant differences in responses based on demographic characteristics, including: 1) underrepresented minorities perceived more microaggressions, less peer support, and more financial concerns than other students; 2) females and nonbinary individuals perceived more microaggressions and more feelings related to imposter phenomenon; and 3) students in science, technology, engineering, and mathematics (STEM) programs reported higher scores for access and opportunity but had lower scores for persistence than non-STEM students. Regression analysis revealed mentor support and financial support positively impacted students' scores for persistence, whereas imposter phenomenon had a negative impact. There were not significant relationships found between persistence and the remaining factors (i.e., access and opportunity, microaggressions, and peer support).This study provides evidence for the structural supports that assist students and recommendations for universities to offer more support to enhance the success of all graduate students and to create a more inclusive climate in graduate education. Cohort models and program-based student work sessions have the potential to scaffold peer support, whereas professional development on mentor support for faculty could assist in developing greater mentor support. Providing financial counseling and greater access to mental health resources could help students in overcoming other barriers. Students would benefit from opportunities to gain experience with academic research and writing, and students with family obligations require flexibility in assistantships and courses. Although each person's graduate experience is highly unique, these analyses helped to elucidate particular aspects that inform concrete steps that could enhance the graduate student experience for "all" students. [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.]