Complex sentence: Emerson was a major figure in epidemiology in the 1920s, founding the American Epidemiological Society in 1927 with Edward Godfrey, an Assistant Professor of Epidemiology at Columbia under Emerson.
Split into simpler sentences: Emerson was a major figure in epidemiology in the 1920s. He founded the American Epidemiological Society in 1927 with Edward Godfrey, an Assistant Professor of Epidemiology at Columbia under Emerson.