In 1794, when war with the Barbary States was expected, Congress ordered the building of six large frigates. One of these was the famous _Constitution_, which is still in existence and about which Dr. Holmes wrote the well-known poem called "Old Ironsides." Through all the earlier years of our history, John Adams used his influence to strengthen our power on the sea; and he was so far successful that he has often been called "The Father of the American Navy." When the War of 1812 began the United States owned a great many gunboats for coast defense, besides seventeen sea-going vessels. It was during this war that the navy especially distinguished itself, and Oliver Hazard Perry made his name famous. [Illustration: A SLOOP OF WAR.] The ships of war in those earlier times were wooden sailing vessels, and they were very slow-goers when compared with the swift cruisers which sail the ocean now. The largest of these vessels were called ships of the line, because they formed the line of battle in any general fight at sea. They usually had three decks, with guns on every deck. The upper deck was often covered over, and on the open deck thus formed above there was a fourth tier of guns. This open deck was called the forecastle and quarter-deck. Some of the largest ships of the line carried as many as 120 guns each; the smallest was built to carry 72 guns. Next in size to these ships were the frigates. A frigate had only one covered deck and the open forecastle and quarter-deck above it, and therefore had but two tiers of guns. The largest frigate carried sixty guns, besides a large pivot gun at the bow. The American frigates were noted for their speed. Still smaller than the frigates were the corvettes, or sloops of war, as they are more commonly called. These had but one tier of guns, and that was on the open deck. They were rigged like the larger vessels, with three masts and square sails. [Illustration: THE STEAM FRIGATE POWHATAN.] The fourth class of vessels included the brigs of war, which had but two masts and carried from six to twenty guns. Equal to them in size were the schooners, which also had two masts, but were rigged fore-and-aft. The guns which they carried were commonly much smaller than those on the sloops and frigates.