A new article on Bloomberg View online this week by Stephen Mihm relates how summer vacations bacame 'a thing' in the U.S. "How Summer Vacation Took Hold in the U.S. A preacher's bestselling book convinced the emerging middle class to escape the cities. Horace Mann finished the job." An Associate Professor of History, Mihm is a contributor to the Ticker at Bloomberg View and author of A Nation of Counterfeiters and Crisis Economics (with Nouriel Roubini).