The document discusses the history and rise of suburbs. It notes that for most of human history, communities were either urban or rural, but after World War 2, suburbs grew in popularity as soldiers returned home. Suburbs are residential neighborhoods located on the outskirts of cities. They rely on cars and infrastructure to connect to jobs in cities. By the 1950s, half of Americans lived in suburbs, which featured housing developments, strip malls, and reliance on automobiles over public transit.