In the 1950s, polio spread throughout the United States. Heartbreakingly, it affected mainly children. Thousands died. Thousands more were paralyzed. Many ended up surviving only in iron lungs, a machine that breathed for polio victims, sometimes for years. Scientists raced to find a vaccine. After a few hard years of widespread quarantine and isolation, the scientists succeeded. The discovery of the polio vaccine was one of the brightest moments in public health history. But a vaccine required Americans to believe in a truth they couldn’t see with their own eyes. It also raised questions of access, of racial equity, and of the federal government’s role in healthcare, questions whose legacy we’re living with today.