 Dr. William Worrall Mayo , the founder of the Mayo Clinic , emigrated from Salford , United Kingdom to the United States in 1846 and became a medical doctor in 1850 . In 1863 , Mayo moved to Rochester , followed by his family the next year . In the summer of 1883 , an F5 tornado struck , dubbed the 1883 Rochester tornado , causing a substantial number of deaths and injuries . Dr. W. W. Mayo worked with nuns from the Sisters of St. Francis to treat the survivors . After the disaster , Mother Alfred Moes and Dr. Mayo recognized the need for a hospital and joined together to build the 27 @-@ bed Saint Marys Hospital which opened in 1889 . The hospital , with over 1100 beds , is now part of the Mayo Clinic , which grew out of the practice of William Worrall Mayo and his sons , William James Mayo ( 1861 – 1939 ) and Charles Horace Mayo . Dr. Henry Stanley Plummer joined the Mayo Brothers ' practice in 1901 . Plummer developed many of the systems of group practice which are universal around the world today in medicine and other fields , such as a single medical record and an interconnecting telephone system . 
