He then transferred and majored in history at Michigan State University. He said that, during this period, he was a particular fan of Ernest Hemingway's writing and came to believe that "the hardest thing to do is write clearly and simply, and make your point in an elegant way". Upon graduation, Hill was called up for the United States Army in 1964, but childhood asthma saw him ruled ineligible. This forced him to think about what he wanted to do for a career. "When you are that age, you think you are going to be in the army two years, it's a huge amount of time. You don't bother worrying about what you are doing. Suddenly, this whole thing was upon me."