Achievement in STEM (Science, Technology, Engineering and Mathematics) is a marker of racial inequality. Despite making up 13 percent of the U.S. populace, Black representation in STEM education and the STEM workforce is far from equitable. A reversal of this trend, however, exists at Historically Black Colleges and Universities (HBCUs), where HBCU graduates represent nearly 18 percent of STEM baccalaureate degrees awarded to Black students. Through a multi-site case study of STEM education at four HBCUs, I interviewed students, faculty and administrators involved in services and programs (i.e. undergraduate research, mentoring) specific to supporting students in the gateway courses. Validation Theory and Science Identity Theory were used to inform the overall design--collection and analysis of data--of the study. I found that these services make a meaningful difference in the achievement of students in STEM by providing them with sound relationships and effective study skills, embedded within a culture of family, that help them overcome the challenges associated with the gateway courses. This difference can also be attributed to the multiple roles that faculty plays outside the classroom to address the challenges that externally bear on their students' achievement. By understanding how these four HBCUs have helped their students overcome this critical stage in the STEM educational pipeline, findings help identify salient practices and strategies that encourage minority student learning and persistence that could be informative to other minority serving institutions and majority institutions struggling to support these student populations. Lastly, this study also demonstrates the ongoing importance of HBCUs in improving minority access to opportunities in the STEM workforce.