How Many Military Branches Are There and What Does Each Branch Do?

By Sydney Johnson

With about 1.3 million active-duty service members, the U.S. Armed Forces is one of the largest militaries in the world. Together, the six branches work to protect and defend the country’s people and interests.

Though there are similarities across the branches - and they are unified in one great mission of safeguarding the U.S. from any and all threats - they each have their own niche.

1. Army

Established on June 14, 1775, the U.S. Army is the oldest branch of the military. The Army was essential to the U.S. gaining independence because of the bravery of its soldiers during the Revolutionary War. Today, more than two centuries later, its members continue to defend and protect the country and its people.

The Army serves the country primarily by land and air. However, it does have a marine presence. These sea-savvy soldiers like to be called “Army mariners.” Within the branch, there are also several elite groups which receive specialized training - like the Rangers and the Night Stalkers - so they are equipped to handle unique combat situations.

2. Navy

The U.S. Navy is known for protecting the country by sea. However, even though they do that and do it well, they also serve on land and in the air. Within the service, members can choose to focus on one of more than 60 career specialties such as engineering, aviation and medicine.

A Basic Underwater Demolition/SEAL (BUD/S) instructor directs SEAL candidates participating in strength and conditioning training with logs at Naval Special Warfare Center in Coronado, CA. | Photo credit Petty Officer 1st Class Anthony Walker

A very famous elite group within the Navy is the Sea, Air and Land Forces - better known as the SEALs. They undergo some of the most physically demanding military training so they can execute the most challenging of missions. Their very specialized preparation consists of initial training (which takes more than a year to complete) followed by about 18 months of pre-deployment training, ensuring SEALs are ready for just about any circumstances.

3. Marines

Although the U.S. Marine Corps is technically part of the Department of the Navy, it does stand alone as a separate branch of the military. It wasn’t always part of the Navy, though. Founded in 1775, the Marine Corps was actually an independent service until 1834. At first, President Andrew Jackson wanted to reorganize and add it to the Army. However, after some conversations, Congress added it to the Navy, making them “sister services” from then on.

The Marines are often the first on the ground in combat situations, leading the charge when conflict arises. They also serve on Navy ships, protect Naval bases and guard U.S. embassies.

Photo credit Lance Cpl. Colton Garrett

Marines patrol during a simulated embassy reinforcement.

4. Coast Guard

The Coast Guard protects U.S. waterways, ports, and shores, as well as acts as a first responder on our coasts. The Coast Guard is especially unique because it’s not only a military branch, but also a federal law enforcement agency.

Though the Navy and Coast Guard are both maritime branches, they have very different missions. While the Navy maintains a war-ready fleet, the Coast Guard keeps our waterways safe by conducting search and rescue missions, protecting the marine environment and stopping the smuggling of illicit drugs into the country. In peacetime, it operates under the Department of Homeland Security, and in wartime, it serves under the Department of the Navy, so it can assist in the defense against foreign threats.

5. Air Force

The Air Force aerially protects United States’ interests at home and abroad. Originally in the early 20th century, the Air Force was created as a unit of the Army, as was known as the Aeronautical Division. It wasn’t until 1947, after World War II, that the U.S. Air Force was founded as a separate branch of the military.

Today, there are more than 332,000 full-time active duty members of the Air Force. Aside from flying some of the fastest planes in the world, these service members work as engineers, medical professionals, lawyers and computer scientists.

Photo credit Senior Airman Noah Sudolcan

Col. Henry R. Jeffress III, 51st Fighter Wing vice commander, performs a pre-flight inspection prior to his debut F-16 Fighting Falcon launch as “Mustang 2” Sept. 2, 2020, at Osan Air Base, Republic of Korea.

6. Space Force

Established just last year on Dec. 20, 2019, the U.S. Space Force is the newest branch of the military. Similar to how we have branches of the military to defend the country by air, land, and sea, the Space Force protects the nation in space.

The Space Force’s duty is to develop military space capabilities, acquire military space systems, mature the military doctrine for space power and organize space forces to present to our Combatant Commands, which are regionalized or functionalized military teams. This is all to protect the interests of both the U.S. and its allies in space.

Previously, the U.S. Air Force Space Command was responsible for these duties, but since the establishment of the Space Force last year, the command’s personnel are currently in the process transferring into the new branch, which will take several more months.

Wait, what about the National Guard?

Florida Air National Guard, 125th Medical Group Detachment 1, set up patient treatment tents, practiced triage, and ran search and rescue operations at Camp Blanding, Florida. | Photo credit Senior Airman Cole Benjamin

Though the National Guard isn’t technically a military branch, it is an important component of the service. It is a combination of the Army National Guard and the Air Force National Guard, which both serve as reserve components of their respective branches.

Each state, most U.S. territories and the District of Columbia has its own National Guard, which can be activated by both governors and the president. When they are called upon, these part-time service members are ready to respond to reconstruction efforts, natural disasters and some overseas combat missions. In 2020 alone, tens of thousands of National Guard members were activated to help fight the coronavirus and respond to other natural disasters.

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