In her recent book, The Ideas That Made America: A Brief History, Professor Ratner-Rosenhagen examines the history of American thought from the pre-contact period to the present day. She is one of the most distinguished intellectual historians of her generation. The book contains insights into key moments of American intellectual transformation, from the Enlightenment, transcendentalism, and Social Darwinism to progressivism, conservatism, and postmodernism. It explores American history by way of ideas, thinkers, and intellectual movements.