Evidence of sporadic epidemics of polio predate recorded history.
1789, British physician Michael Underwood provides first clinical description of the disease.
1840, Jacob Heine describes the clinical features of the disease as well as its involvement of the spinal cord.
1894, first outbreak of polio in epidemic form in the U.S. occurs in Vermont, with 132 cases.
1908, Karl Landsteiner and Erwin Popper identify a virus as the cause of polio by transmitting the disease to a monkey.
1916, large epidemic of polio within the United States.
1921, Franklin Delano Roosevelt (FDR) contracts polio at age 39. His example has a major impact on public perceptions of individuals with disabilities. Although FDR is open about having had polio, he conceals the extent of his disability.
1927, FDR forms Warm Springs Foundation in Georgia for polio rehabilitation.
1929, Philip Drinker and Louis Shaw develop the “iron lung” to aid respiration.
1930s, two strains of the poliovirus are discovered (later it was determined that there were three).
1931, scientists create the first filter able to trap viruses.
1933, FDR inaugurated president of the United States.
1934, the first of the Birthday Balls to raise funds for the Warm Springs Foundation is held on FDR's birthday January 30.
1935, Maurice Brodie and John Kolmer test polio vaccines, with disastrous results.
1938, FDR founds the National Foundation for Infantile Paralysis, known today as the March of Dimes.
1940s, Sister Kenny, an Australian nurse, comes to the U.S. to promote her new treatment for polio, using warm compresses to relax painful, contracting muscles and massage for rehabilitation.
1945, FDR dies on April 12.
1947 - 50, Dr. Jonas Salk is recruited by the University of Pittsburgh to develop a virus research program and receives grant to begin a polio typing project. He uses tissue culture method of growing the virus, developed in 1949 by John Enders, Frederick Robbins, and Thomas Weller at Harvard University.
1953, Salk and his associates develop a potentially safe, inactivated (killed), injected polio vaccine.
1954, nearly two million children participate in the field trials.
1955, news of the success of the trials is announced by Dr. Thomas Francis in a formal press conference at Ann Arbor, Michigan, on April 12, the tenth anniversary of FDR's death. The news was broadcast both on television and radio, and church bells rang in cities around the United States.
1955 - 57, incidence of polio in the U.S. falls by 85 - 90%.
1957 - 59, mass clinical trials of Albert Sabin's live, attenuated vaccine in Russia.
1962, the Salk vaccine replaced by the Sabin vaccine for most purposes because it is easier to administer and less expensive.
1968, passage of the Architectural Barriers Act, requiring that all federally financed buildings be accessible to people with disabilities.
1979, last case of polio caused by “wild” virus in U.S.; last case of smallpox in the world.
1980s, post-polio syndrome identified by physicians and people who had polio.
1980, the first National Immunization Day for polio held in Brazil.
1981, poliovirus genome sequence published.
1985, Rotary International launches PolioPlus program.
1988, Rotary International, PanAmerican Health Organization, World Health Organization, Centers for Disease Control, UNICEF begin international campaign to stop transmission of polio everywhere in the world.
1990, Passage of the Americans with Disabilitites Act (ADA), providing broad legal protections for people with disabilities.
1999, inactivated polio vaccine replaces oral polio vaccince as recommended method of polio immunization in the United States.
2005, 50th anniversary of the announcement of the Salk vaccine on April 12.