Background/Context: This opening article, like the other articles in this special issue, is situated in scholarship that attempts to understand the racialized nature of mathematics education in the United States and to examine the racial identities of students and teachers in the context of school mathematics. It is designed to respond to the current (mathematics) education policy context that largely ignores teachers' experiential and cultural knowledge while stressing the importance of teachers' content knowledge and academic achievement. Purpose/Objective/Research Question/Focus of Study: This article presents theoretical perspectives and research questions concerning the knowledge and other resources that African American teachers bring to teaching mathematics, perspectives and questions that are taken up in the five subsequent articles in this special issue. Setting: The cases developed in this special issue were developed from observations of the introductory algebra classes of, and interviews with, two well-respected African American teachers in one neighborhood high school in a large urban school district that serves a predominantly African American student population. Research Design: This opening article frames two case study papers and two analysis papers that report on findings from a large-scale qualitative study of the racialized identity and instructional approaches of two of the six African American mathematics teachers studied in the Mid-Atlantic Center for Mathematics Teaching and Learning Algebra 1 Case Studies Project. Conclusions/Recommendations: Together with the other articles in this special issue, this work contributes to the development of more sophisticated attempts to integrate understandings of race into the work of the mathematics education community. It challenges taken-for-granted notions of the knowledge base and resources needed to be an effective mathematics teacher of African American students in under-resourced large urban schools.