This study investigated an approach to teaching students to evaluate online information in the context of a high school history class. Over the course of a semester, I collaborated with a teacher to teach and refine a series of eight lessons focused on "civic online reasoning." We aimed to use students' historical reading as a bridge to help them learn to evaluate online sources; however, tensions also arose between historical reading and civic online reasoning. We negotiated the content focus of the lessons. We asked students to investigate historical questions with contemporary ramifications instead of strictly civic questions, but we still balanced a need for students to build civics content knowledge to effectively evaluate online information. We also negotiated the degree to which we presented online evaluations as requiring different strategies than print historical sources. We emphasized similarities in the evaluative approaches but also learned to be explicit about differences. As teachers consider how to help students learn to evaluate online information, the question of how such lessons might be incorporated into existing disciplinary goals is a critical one. This study presents an in-depth analysis of design efforts in one such case.