United States Armed Forces The United States Armed Forces were the overall unified military forces of the United States before the Great War , composed of the United States Army , United States Marine Corps , United States Navy , United States Coast Guard , and the United States Air Force . The President served as the Commander - in - Chief of the military , with the Secretary of War , Department of War , and Department of Defense acting as the principal organ by which military policy was carried out . Two centuries after the Great War , a new generation of descendants from the United States Armed Forces were ultimately reorganized into a post - nuclear variant of an ancient United States government bureau called the Department of the Army , otherwise known as the Enclave ' s military sub - division . Enclave troopers are trained , conditioned and disciplined accordingly with advanced training regimens and techniques that diverge directly from that of the old Armed Forces ' more specialized , black op units . The Brotherhood of Steel on the other hand , was originally created by U . S . Army soldiers who rebelled against their standing orders and went AWOL while they were stationed inside of the Mariposa Military Base . Descendants of these renegade soldiers that originally gave birth to the Brotherhood , likely still serve in some form or another in one or more of the various cells of the Brotherhood today . New initiates into the Brotherhood are conditioned using older , slightly less refined U . S Armed Forces techniques than those that the Enclave utilizes that have been passed down in the Brotherhood for centuries to the succeeding generations comprising it after its creation . Background . Pre - War . The Armed Forces have a history dating back to 1754 , even before the official establishment of the country by the Declaration of Independence on July 4 , 1776 . The Continental Army , Continental Navy , and Continental Marines were created by the Second Continental Congress in order to defend the newly formed United States of America against the British Empire in the American Revolutionary War . By 2077 , the United States Armed Forces were the world ' s most powerful military force . Their only rival was the People ' s Liberation Army of China , both of whose Armed Forces clashed during the Sino - American War in the Alaskan campaign ( which included Anchorage ) and numerous offensive campaigns waged in China . The Armed Forces were primarily using energy weapons ( laser and plasma ) in the field , although due to slow production rates , many troops , in particular , those stationed on the Anchorage Front Line were still using regular firearms ( such as the R91 assault rifle ) . Regular infantrymen , regardless of specialization , wore polymer combat armor ( Anchorage troops used special winterized versions ) while suits of power armor were reserved for Mechanized Cavalry units and special detachments ( e . g . Colonel Spindel ' s group at Mariposa ) . In a supportive role , the Army deployed robots ― Sentry bots and combat versions of the popular Mister Handy ― Mister Gutsy . They used hulking APCs to transport their troops and provide cover in combat . Aerial support was to be provided by next - generation helicopters , the VB - 02 Vertibird s , though they were scheduled to enter service in 2085 , prototypes may have seen combat at Anchorage . Fighter support was common and as such many patrolled the U . S . coastline and its national waters . Post - War . With the nuclear holocaust of 2077 and the dissolution of the chain of command , the U . S . Armed Forces effectively ceased to exist , becoming groups of isolated soldiers with no coordination . Two groups , the Enclave and the Brotherhood of Steel , were founded by former members of the United States Armed Forces . Furthermore , it is implied that the members of the United States ' Armed Forces inevitably diffused into the general wastelander population , with some sections stratifying themselves based off perceived military heritage , such as the Desert Rangers of the Texas Commonwealth . Branches . Army . A year before the Resource Wars , the United States Army helped in the invasion of Mexico to protect U . S . oil interests in the region . Army units were being deployed in Alaska at higher levels than before following the establishment of the Anchorage Frontline in 2059 . Much more veritable quantities of troops were transported to the state after the Chinese invasion of Alaska in the winter of 2066 and 2067 . The United States Army was utilized in the 2072 - 2076 annexation process of Canada and were decisive in defeating the Canadian military and suppressing resistance movements . Later on , in the Sino - American War , Army units were deployed in China proper and its annexed territories with the USMC following the invasion of the supra in 2074 . As unrest at home grew in the last years of the war several Army units were deployed within the United States to maintain law and order . National Guard . The National Guard was a reserve component of the United States Army and served as a domestic defense and disaster relief force during peacetime . However , during wartime , they were deployed abroad as front - line troops alongside other Army units . In the months and years immediately succeeding the Great War , remnants of the National Guard attempted to retain order and law in the United States , assisted by civilian elements such as nurses , and potentially police , as was seen in Germantown . However , due to the high attrition rate suffered as a result of the radiation and anarchy , most , if not all , National Guard units were whittled down by moralities , along with desertion , and eventually disbanded . Robotics Division . The United States Army Robotics Division was the branch of the army dedicated to the handling and deployment of military robots and associate hardware , and also performed services within lines of robotic research , such as the facility under the RobCo sales & service center in Boston . Known robots used by the division include the assaultron , cyberdog , eyebot , Mister Gutsy , protectron , robobrain , and sentry bot . Military Police . The Military Police Division was a branch that provided security at military installations around the country . They had a presence at Robotics Technology Facility RB - 2851 in Boston and were known to have responded to incidents at the South Boston military checkpoint . Marine Corps . The Marine Corps served in the American counter invasion of China due to their specialization in amphibious operations . They took part in the Yangtze Campaign and Gobi Campaign between 2066 - 2077 , and were equipped with desert camouflaged armors . Members of the Marine Corps stationed in the Mount Desert Island Naval Facility before the Great War were equipped with a different model of armor . Navy . Before 2077 , the US Navy saw widespread deployment , most notably during the Anchorage Reclamation , with the incident between USS Ebon Atoll and USS Interference . The Navy furthermore had bases throughout the United States , notably the Naval Recruiting Center in Maryland ' s Point Lookout State Park and the Mount Desert Island Naval Facility in Maine . After the war , there are few remaining signs of the Navy , with the only two known intact ( relatively speaking ) major ships being a Aircraft Carrier whose original name has been long lost and is known as Rivet City , located in Washington D . C , and the nuclear missile submarine USS " Democracy " , located on Mount Desert Island . There are also the wrecks of some smaller support vessels , such as the tugboat the USS " Riptide " . Air Force . The United States had many Air Force bases throughout the country , some of which are , Adams Air Force Base in Maryland , Nellis Air Force Base in the Mojave Desert , and Elmendorf Air Force Base in Alaska . Some Air Force officers were astronauts for the United States Space Administration . Coast Guard . The United States Coast Guard operated at least one base in the country : the Coast Guard Pier in Massachusetts . They were involved in an operation to stop chem smuggling along the Charles River .