The open-classroom movement originated in British public elementary schools after World War II. American educators who adopted the trend viewed informal education--or, as they came to call it, open classrooms or open education--as an answer to both the American education system's critics and the problems of U.S. society. Open classrooms' focus on students' "learning by doing" resonated with those who believed that America's formal, teacher-led classrooms were crushing students' creativity. In this article, the author discusses the rise and fall of open classrooms in relation to changes in the public's perspective on education. He concludes that while open classrooms may have been a fad in the sense that, like hula hoops and pet rocks, they had soared onto the scene and then disappeared without a trace, ignoring their former existence would miss the deeper meaning of open classrooms as yet another skirmish in the ideological wars that have split educators and the public since the first tax-supported schools opened their doors in the early 1800s.