Abstract: Geographic information systems (GIS) are an increasingly powerful and essential technology in many professional fields, yet they are not yet present in applicable parts of the K-12 curriculum. This paper presents an excerpt from a classroom-based study of curriculum integration and teacher decision-making using GIS to teach aspects of American History. We highlight one lesson within a longer sequence, examining the demography of the African American experience between 1860 and 1910. The teacher introduces students to a researcher-built GIS coverage, modeling the use of the interface and simple tools. Student observations and questions become launching points for further refinement in the instruction, both in terms of the content and the technology. Considerations for teacher education regarding GIS include suggestions for map design, data selection, and prioritizing pedagogy over technology.