Since 1889, in American state Minnesota, brothers William Mayo and Charles Mayo had built an international reputation for surgical skill at their Mayo Clinic, by 1906 performing some 5,000 surgeries a year, over 50% intra-abdominal, a tremendous number at the time, with unusually low mortality and morbidity. Though originally distancing themselves from routine medicine and skeptical of laboratory data, they later recruited Rosenow from Chicago to help improve Mayo Clinic's diagnosis and care and to enter basic research via experimental bacteriology. Rosenow influenced Charles Mayo, who by 1914 published to support focal infection theory alongside Billings and Rosenow.