Silent Spring, by Rachel Carson (1962). The book that gave birth to the environmental movement
The Feminine Mystique, by Betty Freidan. (1960) The book that started the feminist movement
Atlas Shrugged and The Fountainhead, by Ayn Rand. Two key works in the modern Conservative movement
The Jungle by Upton Sinclair (1904). One of the key books of the muckraking period; led to reform of food safety laws. Sinclair wrote is as a call for Socialism