Sent by the Virginia Company, three ships carrying settlers landed at a defensible spot on the James River. The site's brackish water and mosquito-ridden marshes proved deadly, and within nine months two-thirds of the colonists were dead from disease and starvation. Despite the catastrophic losses, Jamestown survived and became the seed of English colonization in America.

English physician Edward Jenner had long observed that dairy workers who caught cowpox seemed immune to smallpox, a disease that killed a third of its victims and disfigured many survivors. He took material from a lesion on milkmaid Sarah Nelmes and inserted it into two small cuts on the arm of his gardener's son. Weeks later he exposed the boy to smallpox itself; Phipps did not fall ill, proving the principle of vaccination.

Commissioned by President Thomas Jefferson after the Louisiana Purchase doubled the size of the United States, the expedition set out up the Missouri River in a keelboat and two pirogues. Over the next two and a half years they would travel roughly 8,000 miles, map vast unknown territory, catalog hundreds of new plant and animal species, and encounter dozens of Native American nations, guided crucially by the Shoshone woman Sacagawea.

Reading the Declaration of Independence at the Tel Aviv Museum, Ben-Gurion announced the creation of a Jewish state in Palestine, fulfilling a decades-old Zionist aspiration in the wake of the Holocaust. The declaration was timed to take effect at midnight as the British Mandate expired. Within hours, the United States extended recognition, and neighboring Arab states invaded, igniting the first Arab-Israeli war.

Skylab reached orbit but immediately suffered a critical setback: its micrometeoroid shield tore away during launch, taking a solar panel with it and jamming another, leaving the station overheating and underpowered. NASA scrambled to redesign a repair mission in just ten days. The first crew, launched eleven days later, successfully deployed a makeshift parasol sunshade and freed the jammed panel, saving the station.