His writings, both in class and out, had been lengthy since his years at Horace Mann. A short story he wrote for "The Princeton Tiger", the school's humor magazine, took up almost an entire issue. His 235-page long senior thesis on existentialism in Hemingway, titled "Heading Out: A Study of the Development of Ernest Hemingway's Thought", was so long, Caro claims, that the university's English department subsequently established a maximum length for senior theses by its students. He graduated "cum laude" in 1957.