Increasing the racial and gender diversity of the teacher and school leader workforce in public schools has been the focus of policy efforts in dozens of states. Using administrative longitudinal data for all Texas public schools over a 20-year period, this dissertation consists of three chapters examining the role of relational demography and network connections in hiring and retention of Black and Hispanic male and female teachers and principals, drawing attention to the ways that racial and gender congruence between hiring managers and employees affect the composition of the teacher and school leader workforce. The first chapter estimates causal effects of school principal racial and gender congruence with teachers on the composition of new teacher hires, as well as on the probability of teacher attrition, finding that Black and Hispanic principals hire more Black and Hispanic teachers, respectively, relative to a white principal in the same school, and that effects are larger for hires of Black and Hispanic female teachers by Black and Hispanic female principals. Racial and gender congruence affect teacher attrition as well, with specific effects varying across race-sex groups. The second chapter examines the role of social closure in hiring into school leadership for individuals with principal certification, finding that Black and Hispanic candidates with employment network connections to a Black or Hispanic superintendent were more likely to be hired only when they shared a network connection with a same-race superintendent. The third chapter estimates causal effects of superintendent racial and gender congruence with principals on the racial and gender composition of new principal hires as well as on principal retention, finding that Black superintendents hire more Black principals of both sexes relative to a white superintendent in the same district, with effects on principal attrition differing across race-sex groups. [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.]