Brothers and surgeons (doctors who perform operations), William Mayo and Charles Mayo, along with their father William Worrall Mayo, founded the world-famous Mayo Clinic in 1864. It was located in Rochester, Minnesota. The Mayo Clinic is a nonprofit medical practice and medical research group based in Rochester, Minnesota. It employs more than 4,500 physicians and scientists and 58,400 administrative and allied health staff. The practice specializes in treating difficult cases through tertiary care. It spends over $660 million a year on research and employs over 3,000 full-time research personnel. The clinic was founded in 1864 and is very famous world wide. Even some kings and princes of other nations go there for health care .