Several essential interactions or experiences that had an influence on preservice teachers' learning and understanding about urban education and diversity are described and discussed. In particular, the author introduces a developmental typology that was used to analyze the preservice teachers' learning and understanding as a result of a course designed to help preservice teachers develop the knowledge, skills, dispositions, and attitudes necessary to teach in highly diverse and urban school contexts. These developmental interactions that made a critical difference in the preservice teachers' learning included cultural and racial awareness and insight, critical reflection, and a bridge between theory and practice. Understanding the influence of courses in teacher education that endeavor to provide learning spaces for preservice teachers is especially important as we document the most salient ways to provide all prospective teachers with what they need to make meaningful and significant differences in P-12 urban classrooms. (Contains 2 tables, 1 figure, and 3 notes.)