The purpose of this study was to investigate teachers' perceptions, understanding, and use of inquiry-based instruction in the social studies, to assess the impact of inquiry-based units on instruction, to detail implementation successes and challenges reported by teachers when implementing inquiry-based instruction, and to provide recommendations for future efforts. Teachers' perceptions of teaching and learning, particularly their beliefs about inquiry-based instruction, changed during the study. Throughout the study, teachers' perceptions and beliefs about teaching social studies had an impact on how they planned, implemented and reflected on inquiry-based instruction. Many of the teachers changed their perceptions and began regularly teaching with an inquiry-based focus, and some changed from a belief system that focused on a teacher-centered model to a more student-centered focus. [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.]