The Army, Marine Corps, Navy, Air Force, Space Force and Coast Guard are the armed forces of the United States. The Army National Guard and the Air National Guard are reserve components of their services and operate in part under state authority.

Branches are listed by order of oldest serving branch. The Navy is listed after the Marine Corps due to being disbanded after the Revolutionary War.

Army

The Second Continental Congress founded the Army on June 14, 1775, (also Flag Day) as the Continental Army. The oldest and largest service in the United States military, the Army provides the ground forces that protect the United States. Originally formed to protect the freedom of the first 13 colonies, the Army has evolved and grown from this small militia force into the world’s premier fighting force.

The Army exists to serve the American people, to defend the Nation, to protect vital national interests, and to fulfill national military responsibilities. Just because the Army is the oldest doesn’t mean you won’t be working with today’s most high-tech equipment. Most of what the army does, it does on land.

Marine Corps

The United States Marine Corps was established on Nov. 10, 1775, to augment naval forces in the Revolutionary War. The recruiting headquarters was set up by Capt. Samuel Nicholas in the Tun Tavern on Water Street in Philadelphia, which is considered to be the birthplace of the Marines.

After success in many campaigns, the Corps was abolished at the close of the Revolutionary War for reasons of economy. On July 11, 1798, Congress ordered the creation of the Corps, named it the United States Marine Corps and directed that it be available for service under the Secretary of the Navy.

The Corps celebrated its birthday, or Marine Corps Day, on July 11 from 1799 until 1921 when the date was permanently changed to Nov. 10 to commemorate the establishment of the Corps to aid in the Revolutionary War.

Navy

The Continental Congress’s resolution to procure two armed vessels, adopted in Philadelphia, Pennsylvania, on Oct. 13, 1775, was the original legislation out of which the Continental Navy grew. Within a few days of that vote, Congress established a Naval Committee, which directed the purchasing, outfitting, manning, and operations of the first ships of the new Navy, drafted naval legislation, and prepared rules and regulations to govern the Navy’s conduct and internal administration. Philadelphia was also the port where the purchase and outfitting of the first four vessels of the Continental Navy took place.

Because the Continental Navy began in Philadelphia on Oct. 13, 1775, the Navy claims that date as its birthday. A logical corollary would be to recognize Philadelphia as the Navy’s birthplace. The Navy, however, also honors the significant naval roles that many other towns played in the American Revolution and does not recognize any as its sole place of origin.

The Revolutionary War was ended by the Treaty of Paris in 1783, and by 1785, the Continental Navy was disbanded and the remaining ships were sold. The frigate Alliance, which had fired the last shots of the American Revolutionary War, was also the last ship in the Navy.

Under first President George Washington, threats to American merchant shipping by Barbary pirates from four North African Muslim States in the Mediterranean led to the Naval Act of 1794, which created a permanent standing U.S. Navy.

Air Force

On Aug. 1, 1907, the U.S. Army Signal Corps established a small Aeronautical Division to take “charge of all matters pertaining to military ballooning, air machines and all kindred subjects.”

The Signal Corps began testing its first airplane at Fort Myer, Va., on Aug. 20, 1908, and on Sept. 9, Lt. Thomas E. Selfridge, flying with Orville Wright, was killed when the plane crashed. He was the first military aviation casualty. After more testing with an improved Wright Flyer, the Army formally accepted this airplane, identified as “Airplane No. 1,” on Aug. 2, 1909.

The National Security Act of 1947 became law on July 26, 1947. It created the Department of the Air Force, headed by a secretary of the Air Force. Under the Department of the Air Force, the act established the United States Air Force.

Space Force

Initially formed as Air Force Space Command on Sept. 1, 1982, the Space Force was established as an independent military branch on Dec. 20, 2019, with the signing of the United States Space Force Act, part of the National Defense Authorization Act for 2020.

Coast Guard

The Coast Guard’s official history began on Aug. 4, 1790, when the first Congress authorized the construction of 10 vessels to enforce federal tariff and trade laws and to prevent smuggling. Known variously through the 19th and early 20th centuries as the Revenue Marine and the Revenue Cutter Service, the Coast Guard expanded in size and responsibilities as the nation grew.

The service received its present name in 1915 under an act of Congress that merged the Revenue Cutter Service with the Life-Saving Service, thereby providing the nation with a single maritime service dedicated to saving life at sea and enforcing the nation’s maritime laws.

The Coast Guard is one of the oldest organizations of the federal government and until Congress established the Navy Department in 1798, they served as the nation’s only armed force afloat. The Coast Guard protected the nation throughout their long history and served proudly in every one of the nation’s conflicts. Our national defense responsibilities remain one of our most important functions even today.

Since 2003, the Coast Guard has operated as part of the Department of Homeland Security, serving as the nation’s front-line agency for enforcing the nation’s laws at sea, protecting the marine environment and the nation’s vast coastline and ports, and saving life. In times of war, or at the direction of the president, the Coast Guard serves under the Navy Department.