Although implemented in 1975, the inclusion of students with special needs into the mainstream general education environment has taken a slow path. Now in an age where federal and state mandates affect the ways in which schools are run, the least restrictive environment mandate has been met with increasingly wide acceptance. In order for all students to meet the demands of increased rigor, inclusionary models are being incorporated by campus-level principals in order to allow students with the special needs the same access as their general education peers. The purpose of this study was to explore what principal characteristics are most effective for implementing inclusion models in which students with disabilities are successful academically and socially. The goal was to highlight social justice principals' internal characteristics and beliefs, knowledge and skills, and external practices and how they all merge together to influence teachers and staff, the school climate, and the overall implementation of inclusionary practices for students with disabilities. The research question was approached through a qualitative multiple-case study of 3 secondary campuses. Data were collected through in-depth and semistructured interviews, focus groups, observations and field notes, document reviews, and reflective journal entries. Purposive sampling was used to select the principal participants, and all campuses met criteria outlined by the National Center for Urban School Transformation. Traditional data analysis methods were used in conjunction with the methodological technique of portraiture. Results from the study revealed that each campus principal implemented and nurtured the inclusion model by focusing on personnel development, organizational design, and social justice leadership practices. Within all of these domains emerged specific practices that allowed the leaders to foster healthy campus cultures in which learning, achievement, and equity for all students were the norm. [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.]