This dissertation reports on a qualitative investigation of two research questions: What experiences lead secondary social studies teachers to become passionate and committed to teaching toward social justice? How do these teachers conceptualize and practice teaching toward social justice in the social studies? The study, which employed a life history design informed by a sociocultural approach, examined data from interviews with thirteen secondary social studies teachers whose practice emphasized social justice concepts. Data were interpreted using both narrative analysis and inductive content analysis. A variety of life experiences such as family, schooling, oppression, spirituality, friendships, teaching experience, work experience, community, and media influenced the development of a social justice identity. These experiences shaped the participants' trajectories of identification, particularly in their childhood and adolescence, by either aligning them along a path that valued social justice and/or by promoting resistance to unjust practices that deepened their commitment to social justice. Participants also discussed how they addressed issues of social justice in their practice using techniques that reflected the ideas of critical pedagogy, multicultural education, and democratic citizenship education. The study implies that a greater commitment to social justice practice in the social studies may be facilitated by (1) increasing programming and curriculum in teacher training institutions that address both social justice theory and practice, and (2) developing networks of secondary social studies teachers that support critical reflection and exchange of ideas that promote social justice within both classrooms and schools. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]