While still in college, Wolfe continued playing baseball as a pitcher and began to play semi-professionally. In 1952, he earned a tryout with the New York Giants, but was cut after three days, which he blamed on his inability to throw good fastballs. Wolfe abandoned baseball and instead followed his professor Fishwick's example, enrolling in Yale University's American studies doctoral program. His Ph.D. thesis was titled "The League of American Writers: Communist Organizational Activity Among American Writers, 1929-1942." In the course of his research, Wolfe interviewed many writers, including Malcolm Cowley, Archibald MacLeish, and James T. Farrell. A biographer remarked on the thesis: "Reading it, one sees what has been the most baleful influence of graduate education on many who have suffered through it: It deadens all sense of style." Originally rejected, his thesis was finally accepted after he rewrote it in an objective rather than a subjective style. Upon leaving Yale, he wrote a friend, explaining through expletives his personal opinions about his thesis.