The United States Navy (USN) is the naval warfare service branch of the United States Armed Forces. It is the largest and most capable navy in the world and it has been estimated that in terms of tonnage of its active battle fleet alone, it is larger than the next 13 navies combined, which includes 11 U.S. allies or partner nations. It has the highest combined battle fleet tonnage and the world's largest aircraft carrier fleet.
The U.S. Navy traces its origins to the Continental Navy, which was established during the American Revolutionary War and was effectively disbanded as a separate entity shortly thereafter. After suffering significant loss of goods and personnel at the hands of the Barbary pirates from Algiers, the U.S. Congress passed the Naval Act of 1794 for the construction of six heavy frigates, the first ships of the U.S. Navy.