Modern Era
Ether Day (1846): The First Public Surgery Under Anaesthesia
A public demonstration proved that inhaled ether could prevent pain during surgery, and surgical anaesthesia spread around the world within months.
Region
Americas
Modern Era
Treaty of Guadalupe Hidalgo (1848): Mexico Cedes the Southwest
Mexico ceded about 525,000 square miles, including California and New Mexico, and accepted the Rio Grande border with Texas.
Modern Era
California Gold Rush (1848-1855): The Rush That Built the West
About 300,000 people migrated to California, which became a state in 1850, while its Native population collapsed.
Modern Era
Compromise of 1850: Henry Clay's Last Bid to Save the Union
Five laws passed in September 1850 eased the crisis over slavery in the lands won from Mexico, but the Fugitive Slave Act deepened Northern hostility to slavery.
Modern Era
Singer Sewing Machine (1851): Isaac Singer and the Patent Wars
Singer's design became the most successful sewing machine of the nineteenth century, and his company pioneered patent pooling, mass marketing and instalment sales.
Modern Era
Bleeding Kansas (1854-1861): The Violent Prelude to Civil War
After years of violence and disputed votes, Kansas entered the Union as a free state on 29 January 1861, while the conflict hardened sectional divisions nationwide.
Modern Era
Otis Safety Elevator (1854): The Invention Behind Skyscrapers
Otis showed that a falling lift could be stopped automatically, making passenger elevators acceptable and opening the way to tall buildings.
Modern Era
Mary Seacole in the Crimean War: Her British Hotel at Balaclava
Seacole ran a store, canteen and informal care station for British troops, returned home bankrupt, and became famous through her 1857 memoir.
Modern Era
Reform War (1857-1861): Benito Juarez and Mexico's Liberal Reform
Liberal victory; Juárez's government returned to Mexico City in January 1861 and the separation of Church and state became law, though the conflict left Mexico deeply indebted.
Modern Era
Dred Scott v. Sandford (1857): The Supreme Court and Slavery
By 7 votes to 2 the Court denied Scott his freedom, declared that Black Americans were not citizens and struck down the Missouri Compromise ban on slavery in the territories.
Modern Era
Transatlantic Telegraph Cable (1858-1866): Linking Two Continents
After a short-lived link in 1858, the 1866 cable laid by the Great Eastern gave Europe and North America permanent, near-instant communication.
Prehistory
Hadrosaurus foulkii (1858): America's First Dinosaur Skeleton
Hadrosaurus became the first substantial dinosaur skeleton found in North America, the first evidence that some dinosaurs walked on two legs and, in 1868, the first dinosaur skeleton mounted for public display.