Complex sentence: Although Flexner had never set foot inside a medical school, he was Pritchett's first choice to lead a study of American medical education, and soon joined the research staff at the Carnegie Foundation in 1908.
Split into simpler sentences: Although Flexner had never set foot inside a medical school, he was Pritchett's first choice to lead a study of American medical education. Thus he joined the research staff at the Carnegie Foundation in 1908.