How is historical knowledge transmitted across generations? What is the role of schooling in that transmission? The authors address these questions by reporting on a thirty-month longitudinal study into how home, school, and larger society served as contexts for the development of historical consciousness among adolescents. Fifteen families drawn from three different school communities participated. By adopting an intergenerational approach, the authors sought to understand how the defining moments of one generation--its "lived history"--becomes the "available history" to the next. In this article, the authors focus on what parents and children shared about one of the most formative historical events in parents' lives: the Vietnam War. Drawing on notions of collective memory, as articulated by the French sociologist Maurice Halbwachs, the authors sought to understand which stories, archived in historical memory and available to the disciplinary community, are remembered and used by those beyond its borders. In contrast, which stories are no longer widely shared, eclipsed by time's passage and unable to cross the bridge separating generation from generation? The authors conclude by discussing the forces that act to historicize today's youth and suggest how educators might marshal these forces--rather than spurning or simply ignoring them--to advance young people's historical understanding. (Contains 1 table, 4 figures and 74 notes.)