This study examined the historical understanding of students in two elementary classrooms; the purpose of the project was to the investigate the kinds of knowledge students had about history, the way they thought about the topic, the social context in which their understanding had developed, and the way they approached new historical information. The researcher collaborated with the teachers of a fourth-grade and a combined fourth- and fifth-grade classroom to plan and implement history instruction which focused on active student involvement. Data was collected through approximately ninety hours of participant observation, thirty-three open-ended interviews with twenty-nine different students, and the analysis of 278 written compositions produced as part of classroom assignments. Students began the year with a great deal of information about the past, but most of their knowledge centered on aspects of everyday life, rather than the political and diplomatic history that forms the core of most textbooks and curricula. Students had developed their previous historical understanding not primarily from school instruction but from the media and from interactions with relatives. Although students understood some aspects of the interpretive nature of history, they did not fully appreciate the role of evidence in the creation of historical accounts. Students also overnarrativized their historical knowledge: they simplified history into a story of limited temporal and spatial dimensions, and thought of historical development as proceeding in a simple, linear fashion as the result of human rationality. Students also explained historical events in terms of the attitudes and intentions of individuals, and did not understand the role of political or economic institutions in history. Students quickly began to see how the beliefs and attitudes of people in the past were different, but had less insight into why those ideas were different or why they changed over time. This study suggests that instead of ignoring prior historical understanding, instruction at school should build upon the knowledge students bring with them, help students extend and refine their understanding of the nature and purpose of history, and attempt to expand and diversify their perception of change over time.