The Black Teacher Project (BTP) is an organization that supports, develops and sustains Black teachers for schools in the United States. The organization is building a Black teaching force that reflects the diversity and excellence of Black people in the United States. In our pilot year, BTP offered racial affinity-based professional development supports for Black teachers in the San Francisco Bay Area and New York City, and sought to understand the impact on the teachers who participated. This article describes the findings from these supports, including a year-long book study, inquiry groups, and drop-in "Rejuvenation Spaces." A key finding from this initial pilot study is that racial affinity-based professional development decreases isolation and increases retention for Black teachers.