Daniel J. Boorstin The Unknown Unknowns
Daniel Joseph Boorstin (October 1, 1914–February 28, 2004) was an American historian at the University of Chicago, writing on many topics in American history and world history. He was appointed twelfth Librarian of the United States Congress in 1975 and served until 1987. He was instrumental in the creation of the Library of Congress Center for the Book.
—Wikipedia contributors, “Daniel J. Boorstin,” Wikipedia, (accessed June 3, 2016).