The Louisiana Purchase
A decade of political turmoil followed, including the public guillotine executions of King Louis XVI and Queen Marie Antoinette as well as hundreds of French aristocrats and even the leaders of the uprising.
In the ensuing Reign of Terror, no one was safe from the crowd's lust for blood.
Amid the chaos, an enlisted man in the French army, Napoleon Bonaparte, rose to power. He united France in a series of wars, crowned himself Emperor, conquered much of Europe under the French flag ... and ran up an immense national debt.
To raise cash, he sold to the former U.S. Ambassador to France -- President Thomas Jefferson -- an enormous tract of land stretching from the Gulf of Mexico to the Canadian border.
The price: $15 million.
The "Louisiana Purchase" essentially doubled the size of the young United States.