Commissioned in 1798, the Constitution fought in 1803 and 1804 in the Tripolitan War (1801-1805). During a famous battle with the British warship Guerriere in the War of 1812, a cannon shell bounced off the hull of the Constitution, earning the ship the nickname Old Ironsides. The commemorative poem "Old Ironsides" by Oliver Wendell Holmes later saved the ship from dismantling. It is still in commission, the oldest warship in any navy.
In the 17th and 18th centuries, naval powers rated their battleships according to firepower. Fifth-rate and sixth-rate ships had fewer than 40 guns and were not considered powerful enough to fight in the front lines of battle. Classed as frigates, these ships were used to support ships of the line. They performed reconnaissance work, protected their own country's merchant ships, and attacked the merchant ships of enemy nations.
Early frigates were light and fast. They carried three masts and could maneuver well in the close quarters of battle. Galley frigates were outfitted with oars as well as sails, making them even more agile in battle. They also cost less to build and maintain than their giant, heavily armed counterparts. These strengths appealed to the Congress of the United States, which created the United States Navy in 1794 and authorized the construction of six frigates. The United States, the Constitution and the President were armed with 44 guns, while the Constellation, the Chesapeake, and the Congress each had 36 guns, but two were soon upgraded to 38 guns. The Constitution, launched in 1797, earned the nickname Old Ironsides in 1812 for repelling the cannon balls fired by the British frigate Guerriere. Today berthed in Boston, Massachusetts, the Constitution is the oldest ship in the U.S. Navy and the oldest warship afloat.
Several types of smaller battleships also commonly operated in naval warfare in the 17th, 18th, and 19th centuries. The sloop (or corvette, the French equivalent) ranked below the frigate in firepower. Sloops had two masts, carried about 100 men, and were armed with 18 or fewer guns. Sloops ran down privateers, privately owned, armed vessels that preyed on merchant ships.
The brig also saw military action. Two-masted with several square sails, brigs served in many European navies of the 18th century. In the United States the brig Niagara became famous for its part in the defeat of the British at the Battle of Lake Erie in 1813.