Mayo Clinic traces its heritage to the practice of a frontier doctor, William Worrall Mayo, an Englishman who settled in Rochester in 1863.
His two sons joined his medical practice in the 1880s.
As the family's reputation and practice grew, the Mayos invited other doctors to join them. This group of doctors initiated a new idea in American medicine — the multi-specialty group practice. Both Mayo brothers died in 1939, but Mayo Clinic has continued to be guided by the principles and ideals they instituted.
The Mayo facilities in Jacksonville, Fla., and Scottsdale, Ariz., now extend that tradition to new areas of the country.
1863 — Dr. William Worrall Mayo moves to Rochester to examine new recruits for the Union Army. He stays to set up a solo medical practice in 1864, which eventually led to modern-day Mayo Clinic.
1883 — On July 21, a devastating tornado strikes the Rochester region, injuring so many that the Mayos ask Franciscan sisters to serve as nurses.Mother Alfred Moes, founder of the Sisters of St. Francis, proposes to build and staff a hospital if Dr. W.W. Mayo will provide medical care.
1883 and 1888 — Dr. Mayo's two sons, William J. and Charles H., join him in practice after they finish medical school.
1889 — The Franciscan sisters open Saint Marys Hospital with 27 beds.
1892 — First partner added to Mayo family practice. More physicians were invited to join, beginning the concept of medical teamwork. The team approach naturally led to a division of labor specialists in different fields working together.
1901 — Dr. Henry Plummer joins the Mayo practice from a nearby small town. He was instrumental in designing systems to realize the Mayo's concept of group practice; a common medical record; lifts and conveyors for moving records and X-rays; a registration system; and one of the world's first telephone paging systems. These systems, refined over 90 years, still serve well today.
1907 - Patient registration number one given out. Five thousand patients register at "the Mayo's clinic" as it has come to be known.
1915 - Doctors came from all over the world to observe and learn. This led to the organization this year of one of the world's first formal graduate training program for physicians, the Mayo Graduate School of Medicine.
1919 - The Mayos turn over all the assets of the Mayo Clinic to the nonprofit Mayo Properties Association, the forerunner of Mayo Foundation.
1935 - Mayo Clinic Rochester opens first hospital-based blood bank.
1939 - William and Charles Mayo die within a few months of each other. The clinic they founded, however, continues to grow into an internationally known medical center.
1942 -Dr. Earl H. Wood joins a team that developed a pressurized flight suit, aiding Allied efforts to win World War II.
1950 - Drs. Edward C. Kendall and Philip S. Hench are awarded the Nobel Prize for isolation and first clinical use of cortisone.
1955 - Mayo Clinic surgeons completes first series of operations with heart-lung bypass machine.
1969 - Surgeons at Mayo Clinic complete first FDA-approved hip-joint replacement.
1972 - Mayo Medical School opens.
1986 - Mayo Clinic Rochester, Saint Mary's Hospital, Rochester Methodist Hospital integrate.
1986 - Mayo expands outside Minnesota for the first time with the opening of Mayo Clinic Jacksonville.
1987 - Mayo Clinic Scottsdale opens, St. Luke's Hospital, Jacksonville, becomes part of Mayo. Registration number 4 million given out.
1992 - Mayo begins to form regional network of clinics and hospitals. The Decorah (Iowa) Medical Associates is the first existing practice acquired by Mayo, for what is now known as Mayo Clinic Health System.
1995 - Website opens at mayo.edu.
1996 - Mayo Eugenio Litta Children's Hospital opens as part of Saint Marys Hospital.
2001 - Scientists at Mayo Clinic develop first ability to rapidly diagnosis anthrax poisoning following the terrorist attacks of Sept. 11.
2001 - The 20-story Gonda Building opens to patients.
2002 - Mayo Clinic becomes first federally approved multi-center comprehensive cancer center.
2003 - Mayo Clinic and the University of Minnesota enter into a state-funded collaboration called the Minnesota Partnership for Biotechnology and Medical Genomics.
2010 - The Minnesota Partnership launches the "Decade of Discovery" to "optimally treat and ultimately cure" both Type 1 and Type 2 diabetes by 2020.
2012 - The largest concrete pour in Rochester history occurs as construction workers work on Mayo Clinic's proton center at the Richard O. Jacobson Building.
2013 - Mayo Clinic regenerative-medicine specialists begin "first-in-human study" using patients' own cells to heal damaged hearts.
2013 - Mayo Clinic leaders convince the Minnesota Legislature to approve public funding to support Destination Medical Center plans. Combined, Mayo Clinic, private, city, county and state dollars are expected to total $6 billion of investment over the next 20 years in Rochester.
Source: Mayo Clinic, Post-Bulletin archives