Cases of polio trace back as far as ancient times; Egyptian paintings from as early as the 1300s BC depict children with the condition. In 1798, a British doctor named Michael Underwood provided the first clinical description of polio, but it wasn’t until 1840 that physicians Jakob Heine and Karl Oskar Medin formally recognized it as a disease and called it the Heine-Medin disease. The name underwent many changes; for a time, it was called infantile paralysis because the disease affected children far more often than adults, and finally it became more commonly known as its scientific name of poliomyelitis, or polio for short.

The first formally recorded polio epidemics began in Scandinavia in the late 1800s and quickly spread to other parts of the world. In 1916, the United States reported 27,000 cases of polio and 6,000 related deaths. Research revealed that polio is caused by the spread of a virus, but professionals had not yet discovered how to prevent or treat the disease. For 40 years, polio epidemics were rampant, facilitated by the fact that although the flu-like symptoms of many polio cases were slight and did not cause death or paralysis, they would spread to others and manifest in far more serious forms.