On the afternoon of August 19, 1812, about 400 miles southeast of Halifax, Nova Scotia, the USS Constitution knocked the masts off the British warship HMS Guerriere. The battle earned the U.S. ship the nickname "Old Ironsides," in no small part due to the density of American oak, which repelled cannon shots better than the less-dense oak from Europe. Today the USS Constitution, with 215 years of service, is the longest-serving warship in the U.S. Navy.
Back in the 1790s, the U.S. faced an uncertain world of revolutions, rising superpowers, and piracy off the coasts of Africa. The Naval Act of 1794 created the first U.S. Navy ships since the Revolutionary War, including the USS Constitution.
Two very important and competing threats influenced the construction of the USS Constitution. The first was pirate attacks against American merchant ships in the Mediterranean. To outgun these pirates, the ship carried 44 heavy cannons.
The second challenge was the threat of the more-established European navies, which maintained much larger warships than those of the U.S. Called "ships of the line," they were massive, heavily armed, and held hundreds of crewmen and marines. The USS Constitution was built to outgun any ship the same size or smaller, and at the same time to sail faster than any bigger ship.
Crucial to those goals was a narrow body and a lot of sails: 42,710 square feet of sail on three masts, to be exact.
Today, the USS Constitution is both a commissioned naval vessel and a living museum in Boston Harbor.