The number of linguistically and culturally diverse students entering public schools is increasing (Echeverria, Short & Powers, 2006; Williams, 2001) and mainstream teachers are responsible for making content comprehensible for these students (Clegg, 1996; Georgia Department of Education, 2008); however, test scores and graduation rates indicate that English language learners (ELLs), across the nation, are consistently underperforming on content based assessments and failing to complete high school (Carrasquillo & Rodriguez, 2006; Cruz & Thornton, 2009) . Using a constructivist lens and the concept of the instructional dynamic (Ball & Forzani, 2007), this dissertation presents the experiences of the mainstream teacher and 5 ELLs enrolled in an inclusive, single semester, secondary mainstream US Government course. Through vignettes created from observations, interviews, reflections and document analysis, this semester long qualitative case study presents the experiences of the mainstream teacher and ELLs. Constant comparative analysis of data revealed three themes (1) returning to the past; (2) navigating the classroom; and (3) preparing for the future. Continued analysis revealed five assumptions held by both the mainstream teacher and the ELLs which shaped the experiences of the participants within this mainstream classroom: (1) all members of this classroom were capable of achieving success through work; (2) achieving present success was directly linked to lessons learned from the past; (3) facilitating success means seeking to understand and interact with others (4) being a “team player” offers protection from uncomfortable situations; and (5) teachers and students expect content classes to prepare students for the future. The findings of this study capture the complexity of the mainstream classroom and imply that the success of the mainstream teacher and ELLs alike depend upon increasing appropriate professional development which maximizes the instructional knowledge of mainstream teachers, generating a supportive and collaborative school and classroom environment for teachers and students and ensuring the implementation of a relevant and immediate curriculum.