The painter of the Mona Lisa, a pure genius of the Renaissance, sketched in his notebooks objects, machines, and systems that ...

For several centuries, the United States was a slaveholding nation, until a civil war officially brought an end to the practice. Here’s a look back at this dark chapter in the country’s history.

Founder of electromagnetism, André-Marie Ampère gave his name to the unit of electric current. His major work also shaped the ...

Suleiman I, the most dazzling of the Ottoman sultans, illuminated the 16th century, reigning from 1520 to 1566. He was the ...