In 1937, while Lilly was looking for a good medical school, his wealthy and well-connected father arranged a meeting between Lilly and Charles Horace Mayo of the famous Mayo Clinic in Rochester, Minnesota. Following Mayo's advice, Lilly applied and was accepted to Dartmouth Medical School in Hanover, New Hampshire, where he became good friends with Mayo's son, Charles William Mayo. Lilly graduated from Caltech with a Bachelor of Science degree on June 10, 1938, and enrolled at Dartmouth the following September.