Laura Dassow Walls is William P. and Hazel B. White Professor of English at the University of Notre Dame, where she is affiliated with the History and Philosophy of Science Program. Her book The Passage to Cosmos: Alexander von Humboldt and the Shaping of America (2009) was awarded the Modern Language Association’s James Russell Lowell Prize and the Merle Curti Award by the Organization of American Historians. Her next book, Henry David Thoreau: A Life, is forthcoming in 2017.