Plot: After the Second World War, there were deep divisions in America about how to move forward. Should it be a social democracy, in which a benevolent state would look after its most vulnerable citizens? Or should it put its faith in individual enterprise and the free market to provide plenty for all? Simon Schama examines how the filmmaker Charlie Chaplin and author Ayn Rand created radically different visions of how this new postwar world should work, and how writers such as Rachel Carson drew attention to the damage being inflicted on the natural world