The United States Army (USA) is the land warfare service branch of the United States Armed Forces. It is one of the ##### ######### services of the United States, and is designated as the Army of the United States in the United States Constitution, Article 2, Section 2, Clause 1 and United States Code, Title 10, Subtitle B, Chapter 301, Section 3001. As the oldest and most senior branch of the U.S. military in order of precedence,[9] the modern U.S. Army has its roots in the Continental Army, which was formed (14 June 1775) to fight the American Revolutionary War (1775–1783)—before the United States of America was established as a country.