For ten years the historian at the Baseball Hall of Fame, Allen was formerly a feature writer for the Cincinnati Enquirer, served as public relations director for the Reds, and also conducted radio and TV programs in Cincinnati and Philadelphia. Known as “Baseball’s Walking Encyclopedia,” he brought 55 cartons of books and record files with him to Cooperstown. Allen often spent time in small towns ferreting out information about old players. Among his books: The Official History of the Cincinnati Reds, The History of the World Series, The National League Story, and The American League Story. He played a major role in the compilation of the original Baseball Encyclopedia.