Growing and Defending the Nation

In 1803, President Jefferson hoped to buy just the port of New Orleans from France. The French emperor Napoleon, short of money for his wars, offered far more. The territory the United States bought from France in 1803^Q90 was Louisiana: about 828,000 square miles from the Mississippi River to the Rocky Mountains, for about $15 million. Overnight, the country doubled in size, and Lewis and Clark set off to explore it.

That same year, the Supreme Court decided a case called Marbury v. Madison. It ruled that the Court can strike down a law that conflicts with the Constitution, and it confirmed the core job of the judicial branch^Q51: it explains laws, deciding what they mean and whether they follow the Constitution.

Britain, meanwhile, was seizing American sailors at sea. The result was the War of 1812. In 1814, British troops burned the White House and the Capitol. That September, Francis Scott Key watched British ships bombard Fort McHenry in Baltimore through the night. At dawn he saw the American flag still flying and wrote a poem about it. Set to music as The Star-Spangled Banner, it became the national anthem^Q123 by an act of Congress in 1931.