Contemporary American education initiatives mandate half of all English language arts content is non-fiction. History topics, therefore, will increase within all elementary and English language arts middle level classrooms. The education initiatives have rigorous expectations for students' close readings of, and written argumentation about, numerous texts representing multiple perspectives about the same historical event, era, or figure. Practicing English language arts teachers must adjust pedagogy accordingly. They cannot utilize a single, whole-class novel with comprehension questions as an assessment. With teaching experience but not formal training in history-based pedagogy, they are "adaptive experts." This qualitative study explores how English language arts teachers adapt. Six upper elementary and middle level (5th-8th) teachers who recently received graduate-level history education training were given grant money to develop and implement history-based curricula. This inquiry examined their curricular selections and how they integrated history literacy and historical thinking within text-based writing, or historical argumentation. It also evaluates the efficacy of their assessments.