March 26 · This Day in America
Polio was the nightmare every American parent carried into summer. In 1952 alone it struck nearly fifty-eight thousand people, mostly children, leaving wards full of iron lungs and a generation afraid of swimming pools. On this evening Jonas Salk goes on national radio and says it plainly: he has made a vaccine, tested it, and it works. He tried it first on himself and his own family. He will famously refuse to patent it, asking who would patent the sun. The 1953 announcement is preliminary; the great field trial of 1954, the largest in history, will confirm it. But on this night a country that had learned to dread a season hears a scientist say the fear can end. It did.
Source: circulatingnow.nlm.nih.gov
Also on this day · 1804
Less than a year after the Louisiana Purchase doubled the country, Congress passes the Land Act of 1804, shrinking the smallest parcel a person could buy and easing the terms of credit. The idea was radical for its time: that a continent should be sold not to lords and speculators but in pieces a working family could afford. The promise was uneven and the cost to Native nations immense, but the dream of a farm of one's own moved west on this law.
Source: history.state.gov