United States Army The United States Army ( USA ) is the main branch of the United States Armed Forces responsible for land - based military operations . It is the largest and oldest established branch of the U . S . military , and is one of seven U . S . uniformed services . The modern army has its roots in the Continental Army which was formed on 14 June 1775 , to meet the demands of the American Revolutionary War before the establishment of the United States . The Congress of the Confederation officially created the United States Army on 3 June 1784 after the end of the Revolutionary War to replace the disbanded Continental Army . The army considers itself to be descended from the Continental Army and thus dates its inception from the origins of that force . The primary mission of the army is " to fight and win our Nation ’ s wars by providing prompt , sustained land dominance across the full range of military operations and spectrum of conflict in support of combatant commanders . " The army is a military service within the Department of the Army , one of the three military departments of the Department of Defense . The army is headed by the Secretary of the Army , and the top military officer in the department is the Chief of Staff of the Army . The highest ranking army officer is currently the Chairman of the Joint Chiefs of Staff . During fiscal year 2011 , the Regular Army reported a strength of 546 , 057 soldier s ; the Army National Guard ( ARNG ) reported 358 , 078 and the United States Army Reserve ( USAR ) reported 201 , 166 putting the combined component strength total at 1 , 105 , 301 soldiers . Mission . The United States Army serves as the land - based branch of the U . S . Armed Forces . § 3062 of Title 10 US Code defines the purpose of the army as : History . Origins . The Continental Army was created on 14 June 1775 by the Continental Congress as a unified army for the colonies to fight Great Britain , with George Washington appointed as its commander . The army was initially led by men who had served in the British Army or colonial militias and who brought much of British military heritage with them . As the Revolutionary War progressed , French aid , resources , and military thinking influenced the new army . A number of European soldiers came on their own to help , such as Friedrich Wilhelm von Steuben , who taught the army Prussian tactics and organizational skills . The army fought numerous pitched battles and in the South 1780 – 81 sometimes used the Fabian strategy and hit - and - run tactics , hitting where the enemy was weakest , to wear down the British forces . Washington led victories against the British at Trenton and Princeton , but lost a series of battles around New York City in 1776 and Philadelphia in 1777 . With a decisive victory at Yorktown , and the help of the French , the Continental Army prevailed against the British . After the war , though , the Continental Army was quickly given land certificates and disbanded in a reflection of the republican distrust of standing armies . State militias became the new nation ' s sole ground army , with the exception of a regiment to guard the Western Frontier and one battery of artillery guarding West Point ' s arsenal . However , because of continuing conflict with Native Americans , it was soon realized that it was necessary to field a trained standing army . The Regular Army was at first very small , and after General St . Clair ' s defeat at the Battle of the Wabash , the Regular Army was reorganized as the Legion of the United States , which was established in 1791 and renamed the " United States Army " in 1796 . 19th century . The War of 1812 , the second and last American war against Britain , was less successful than the Revolution had been . Despite the Burning of York and Death of Tecumseh which caused his Indian confederacy to collapse , an invasion of Canada failed , and U . S . troops were unable to stop the British from burning the new capital of Washington , D . C . . However , the Regular Army , under Generals Alexander Macomb and Samuel Smith , proved they were professional and capable of defeating the British army during the invasions of Plattsburgh and Baltimore , and the relatively small US Navy , often attached with Marines , earned most of the victory against the Royal Navy at sea . Two weeks after a treaty was signed , Andrew Jackson defeated the British in the Battle of New Orleans and became a national hero . Per the treaty both sides returned to the status quo with no victor . The army ' s major campaign against the Indians was fought in Florida against Seminoles . It took long wars ( 1818 – 1858 ) to finally defeat the Seminoles and move them to Oklahoma . The usual strategy in Indian wars was to seize control of the Indians winter food supply , but that was no use in Florida where there was no winter . The second strategy was to form alliances with other Indian tribes , but that too is no use because the Seminoles had destroyed all the other Indians when they entered Florida in the late eighteenth century . The U . S . Army fought and won the Mexican – American War ( 1846 – 1848 ) , which was a defining event for both countries . The U . S . victory resulted in acquisition of territory that eventually became all or parts of the states of California , Nevada , Utah , Colorado , Arizona , Wyoming and New Mexico . The Civil War was the most costly war for the U . S . in terms of casualties . After most states in the South seceded to form the Confederate States of America , CSA troops opened fire on the Union - held Fort Sumter in Charleston , South Carolina , starting the war . Forces loyal to the United States were commonly called the Union Army during that war . For the first two years Confederate forces solidly defeated the U . S . Army , with a few exceptions . The Confederates had the advantage of defending a very large country in an area where disease caused twice as many deaths as combat . The Union pursued a strategy of seizing the coastline , blockading the ports , and taking control of the river systems . By 1863 the Confederacy was being strangled . Its eastern armies did very well in combat , but the western armies were defeated one after another until New Orleans was lost in 1862 along with the Tennessee River , the Mississippi River was lost in 1863 , and Atlanta fell in 1864 . Grant took command of Union forces in 1864 and after a series of battles with very heavy casualties , he had Lee under siege in Richmond . Lee lost his Confederate capital in April 1865 and was captured at Appomatox Courthouse ; the other Confederate armies quickly surrendered . The war remains the deadliest conflict in American history , resulting in the deaths of 620 , 000 soldiers . Based on 1860 census figures , 8 % of all white males aged 13 to 43 died in the war , including 6 % in the North and 18 % in the South . Following the Civil War , the U . S . Army fought a long battle with several western tribes of Native Americans . By the 1890s the U . S . saw itself as a potential international player . U . S . victories in the Spanish – American War and the controversial and less well known Philippine – American War , as well as U . S . intervention in Latin America and the Boxer Rebellion , gained America more land and power . 20th century . Starting in 1910 , the army began acquiring fixed - wing aircraft . In 1910 , Mexico was having a civil war , peasant rebels fighting government soldiers . The army was deployed to American towns near the border to ensure safety to lives and property . In 1916 , Pancho Villa , a major rebel leader , attacked Columbus , New Mexico , prompting a U . S . intervention in Mexico until 7 February 1917 . They fought the rebels and the Mexican federal troops until 1918 . The United States joined World War I in 1917 on the side of Britain , France , Russia , Italy and other allies . U . S . troops were sent to the front and were involved in the push that finally broke through the German lines . With the armistice in November 1918 , the army once again decreased its forces . The U . S . joined World War II after the Japanese attack on Pearl Harbor . On the European front , U . S . Army troops formed a significant portion of the forces that captured North Africa and Sicily . On D - Day and in the subsequent liberation of Europe and defeat of Nazi Germany , millions of U . S . Army troops played a central role . In the Pacific , army soldiers participated alongside U . S . Marines in capturing the Pacific Islands from Japanese control . Following the Axis surrenders in May ( Germany ) and August ( Japan ) of 1945 , army troops were deployed to Japan and Germany to occupy the two defeated nations . Two years after World War II , the Army Air Forces separated from the army to become the United States Air Force in September 1947 after decades of attempting to separate . Also , in 1948 , the army was desegregated by order of President Harry S . Truman . The end of World War II set the stage for the East – West confrontation known as the Cold War . With the outbreak of the Korean War , concerns over the defense of Western Europe rose . Two corps , V and VII , were reactivated under Seventh United States Army in 1950 and American strength in Europe rose from one division to four . Hundreds of thousands of U . S . troops remained stationed in West Germany , with others in Belgium , the Netherlands and the United Kingdom , until the 1990s in anticipation of a possible Soviet attack . During the Cold War , American troops and their allies fought Communist forces in Korea and Vietnam . The Korean War began in 1950 , when the Soviets walked out of a U . N . Security meeting , removing their possible veto . Under a United Nations umbrella , hundreds of thousands of U . S . troops fought to prevent the takeover of South Korea by North Korea , and later , to invade the northern nation . After repeated advances and retreats by both sides , and the PRC People ' s Volunteer Army ' s entry into the war , the returned the peninsula to the status quo in 1953 . The Vietnam War is often regarded as a low point for the army due to the use of drafted personnel , the unpopularity of the war with the American public , and frustrating restrictions placed on the military by American political leaders . While American forces had been stationed in the Republic of Vietnam since 1959 , in intelligence & advising / training roles , they did not deploy in large numbers until 1965 , after the Gulf of Tonkin Incident . American forces effectively established and maintained control of the " traditional " battlefield , however they struggled to counter the guerrilla hit and run tactics of the communist Viet Cong and the North Vietnamese Army . On a tactical level , American soldiers ( and the U . S . military as a whole ) did not lose a sizable battle . During the 1960s the Department of Defense continued to scrutinize the reserve forces and to question the number of divisions and brigades as well as the redundancy of maintaining two reserve components , the Army National Guard and the Army Reserve . In 1967 Secretary of Defense Robert McNamara decided that 15 combat divisions in the Army National Guard were unnecessary and cut the number to 8 divisions ( 1 mechanized infantry , 2 armored , and 5 infantry ) , but increased the number of brigades from 7 to 18 ( 1 airborne , 1 armored , 2 mechanized infantry , and 14 infantry ) . The loss of the divisions did not set well with the states . Their objections included the inadequate maneuver element mix for those that remained and the end to the practice of rotating divisional commands among the states that supported them . Under the proposal , the remaining division commanders were to reside in the state of the division base . No reduction , however , in total Army National Guard strength was to take place , which convinced the governors to accept the plan . The states reorganized their forces accordingly between 1 December 1967 and 1 May 1968 . The Total Force Policy was adopted by Chief of Staff of the Army General Creighton Abrams in the aftermath of the Vietnam War and involves treating the three components of the army – the Regular Army , the Army National Guard and the Army Reserve as a single force . Believing that no U . S . president should be able to take the United States ( and more specifically the U . S . Army ) to war without the support of the American people , General Abrams intertwined the structure of the three components of the army in such a way as to make extended operations impossible , without the involvement of both the Army National Guard and the Army Reserve . The 1980s was mostly a decade of reorganization . The army converted to an all - volunteer force with greater emphasis on training and technology . The Goldwater - Nichols Act of 1986 created unified combatant commands bringing the army together with the other four military services under unified , geographically organized command structures . The army also played a role in the invasions of Grenada in 1983 ( Operation Urgent Fury ) and Panama in 1989 ( Operation Just Cause ) . By 1989 Germany was nearing reunification and the Cold War was coming to a close . Army leadership reacted by starting to plan for a reduction in strength . By November 1989 Pentagon briefers were laying out plans to reduce army end strength by 23 % , from 750 , 000 to 580 , 000 . A number of incentives such as early retirement were used . In 1990 Iraq invaded its smaller neighbor , Kuwait , and U . S . land forces , quickly deployed to assure the protection of Saudi Arabia . In January 1991 Operation Desert Storm commenced , a U . S . - led coalition which deployed over 500 , 000 troops , the bulk of them from U . S . Army formations , to drive out Iraqi forces . The campaign ended in total victory , as Western coalition forces routed the Iraqi Army , organized along Soviet lines , in just one hundred hours . After Operation Desert Storm , the army did not see major combat operations for the remainder of the 1990s but did participate in a number of peacekeeping activities . In 1990 the Department of Defense issued guidance for " rebalancing " after a review of the Total Force Policy , but in 2004 , Air War College scholars concluded the guidance would reverse the Total Force Policy which is an " essential ingredient to the successful application of military force . " 21st century . After the September 11 attacks , and as part of the Global War on Terror , U . S . and NATO forces invaded Afghanistan in 2001 , displacing the Taliban government . The U . S . Army led the combined U . S . and allied Invasion of Afghanistan in 2001 , and Iraq in 2003 . In the following years the mission changed from conflict between regular militaries to counterinsurgency , resulting in the deaths of more than 4 , 000 U . S service members ( as of March 2008 ) and injuries to thousands more . 23 , 813 insurgents were killed in Iraq between 2003 – 2011 . The lack of stability in the theater of operations has led to longer deployments for Regular Army as well as Reserve and Guard troops . The army ' s chief modernization plan was the FCS program . Many systems were canceled and the remaining were swept into the BCT modernization program . In response to Budget sequestration in 2013 the army is planned to shrink to a size not seen since the WWII buildup . Organization . Army components . The task of organizing the U . S . Army commenced in 1775 . In the first one hundred years of its existence , the United States Army was maintained as a small peacetime force to man permanent forts and perform other non - wartime duties such as engineering and construction works . During times of war , the U . S . Army was augmented by the much larger United States Volunteers which were raised independently by various state governments . States also maintained full - time militia s which could also be called into the service of the army . By the twentieth century , the U . S . Army had mobilized the U . S . Volunteers on four separate occasions during each of the major wars of the nineteenth century . During World War I , the " National Army " was organized to fight the conflict , replacing the concept of U . S . Volunteers . It was demobilized at the end of World War I , and was replaced by the Regular Army , the Organized Reserve Corps , and the State Militias . In the 1920s and 1930s , the " career " soldiers were known as the " Regular Army " with the " Enlisted Reserve Corps " and " Officer Reserve Corps " augmented to fill vacancies when needed . In 1941 , the " Army of the United States " was founded to fight World War II . The Regular Army , Army of the United States , the National Guard , and Officer / Enlisted Reserve Corps ( ORC and ERC ) existed simultaneously . After World War II , the ORC and ERC were combined into the United States Army Reserve . The Army of the United States was re - established for the Korean War and Vietnam War and was demobilized upon the suspension of the draft . Currently , the army is divided into the Regular Army , the Army Reserve , and the Army National Guard . The army is also divided into major branches such as Air Defense Artillery , Infantry , Aviation , Signal Corps , Corps of Engineers , and Armor . Before 1903 members of the National Guard were considered state soldiers unless federalized ( i . e . , activated ) by the President . Since the Militia Act of 1903 all National Guard soldiers have held dual status : as National Guardsmen under the authority of the governor of their state or territory and , when activated , as a reserve of the U . S . Army under the authority of the President . Since the adoption of the total force policy , in the aftermath of the Vietnam War , reserve component soldiers have taken a more active role in U . S . military operations . For example , Reserve and Guard units took part in the Gulf War , peacekeeping in Kosovo , Afghanistan , and the 2003 invasion of Iraq . Army commands and army service component commands . Source : U . S . Army organization Structure . The United States Army is made up of three components : the active component , the Regular Army ; and two reserve components , the Army National Guard and the Army Reserve . Both reserve components are primarily composed of part - time soldiers who train once a month , known as battle assemblies or unit training assemblies ( UTAs ) , and conduct two to three weeks of annual training each year . Both the Regular Army and the Army Reserve are organized under Title 10 of the United States Code , while the National Guard is organized under Title 32 . While the Army National Guard is organized , trained and equipped as a component of the U . S . Army , when it is not in federal service it is under the command of individual state and territorial governors ; the District of Columbia National Guard , however , reports to the U . S . President , not the district ' s mayor , even when not federalized . Any or all of the National Guard can be federalized by presidential order and against the governor ' s wishes . The army is led by a civilian Secretary of the Army , who has the statutory authority to conduct all the affairs of the army under the authority , direction and control of the Secretary of Defense . The Chief of Staff of the Army , who is the highest - ranked military officer in the army , serves as the principal military adviser and executive agent for the Secretary of the Army , i . e . its service chief ; and as a member of the Joint Chiefs of Staff , a body composed of the service chiefs from each of the four military services belonging to the Department of Defense who advise the President of the United States , the Secretary of Defense , and the National Security Council on operational military matters , under the guidance of the Chairman and Vice Chairman of the Joint Chiefs of Staff . In 1986 , the Goldwater - Nichols Act mandated that operational control of the services follows a chain of command from the President to the Secretary of Defense directly to the unified combatant commanders , who have control of all armed forces units in their geographic or function area of responsibility . Thus , the secretaries of the military departments ( and their respective service chiefs underneath them ) only have the responsibility to organize , train and equip their service components . The army provides trained forces to the combatant commanders for use as directed by the Secretary of Defense . Through 2013 , the army is shifting to six geographical commands that will line up with the six geographical unified combatant commands ( COCOM ) : The army is also changing its base unit from divisions to brigade s . When finished , the active army will have increased its combat brigades from 33 to 48 , with similar increases in the National Guard and Reserve forces . Division lineage will be retained , but the divisional headquarters will be able to command any brigade , not just brigades that carry their divisional lineage . The central part of this plan is that each brigade will be modular , i . e . all brigades of the same type will be exactly the same , and thus any brigade can be commanded by any division . There will be three major types of ground combat brigades : In addition , there are combat support and service support modular brigades . Combat support brigades include aviation ( CAB ) brigades , which will come in heavy and light varieties , fires ( artillery ) brigades , and battlefield surveillance brigades . Combat service support brigades include sustainment brigades and come in several varieties and serve the standard support role in an army . Regular combat maneuver organizations . The U . S . Army currently consists of 10 active divisions as well as several independent units . The force is in the process of contracting after several years of growth . In June 2013 , the Army announced plans to downsize to 32 active combat brigade teams by 2015 to match a reduction in active duty strength to 490 , 000 soldiers . The Army has yet to announce cuts to its supporting structure , and many observers think the Army will eventually shrink to around 400 , 000 active duty troops . Within the Army National Guard and United States Army Reserve there are a further eight divisions , over fifteen maneuver brigades , additional combat support and combat service support brigades , and independent cavalry , infantry , artillery , aviation , engineer , and support battalions . The Army Reserve in particular provides virtually all psychological operations and civil affairs units . Special operations forces . US Army Special Operations Command ( Airborne ) ( USASOC ) : Personnel . These are the U . S . Army ranks authorized for use today and their equivalent NATO designations . Although no living officer currently holds the rank of General of the Army , it is still authorized by Congress for use in wartime . Commissioned officers . There are several paths to becoming a commissioned officer including the United States Military Academy , Reserve Officers ' Training Corps , and Officer Candidate School . Regardless of which road an officer takes , the insignia are the same . Certain professions , including physicians , pharmacists , nurses , lawyers , and chaplains are commissioned directly into the army and are designated by insignia unique to their staff community . Most army commissioned officers are promoted based on an " up or out " system . The Defense Officer Personnel Management Act of 1980 establishes rules for timing of promotions and limits the number of officers that can serve at any given time . Army regulations call for addressing all personnel with the rank of general as ' General ( last name ) ' regardless of the number of stars . Likewise , both colonels and lieutenant colonels are addressed as ' Colonel ( last name ) ' and first and second lieutenants as ' Lieutenant ( last name ) . ' Warrant officers . Warrant officers are single track , specialty officers with subject matter expertise in a particular area . They are initially appointed as warrant officers ( in the rank of WO1 ) by the Secretary of the Army , but receive their commission upon promotion to chief warrant officer two ( CW2 ) . By regulation , warrant officers are addressed as ' Mr . ( last name ) ' or ' Ms . ( last name ) . ' However , many personnel address warrant officers as ' Chief ( last name ) ' . Enlisted soldiers say " sir " or " ma ' am " when addressing them . Enlisted personnel . Sergeants and corporals are referred to as NCOs , short for non - commissioned officers . This distinguishes them from specialists who might have the same pay grade , but not the leadership responsibilities . Privates ( E1 and E2 ) and privates first class ( E3 ) are addressed as ' Private ( last name ) ' , specialists as ' Specialist ( last name ) , corporals as ' Corporal ( last name ) ' , and sergeants , staff sergeants , sergeants first class , and master sergeants all as ' Sergeant ( last name ) . ' First sergeants are addressed as ' First Sergeant ( last name ) ' and all sergeants major as ' Sergeant Major ( last name ) ' . Training . Training in the United States Army is generally divided into two categories – individual and collective . Basic training consists of 10 weeks for most recruits followed by AIT ( Advanced Individualized Training ) where they receive training for their MOS ( military occupational specialties ) . While the length of AIT school varies by the MOS , some individuals MOS ' s range anywhere from 14 – 20 weeks of One Station Unit Training ( OSUT ) , which combines Basic Training and AIT . The length of time spent in AIT depends on the MOS of the soldier . Depending on the needs of the army , Basic Combat Training is conducted at a number of locations , but two of the longest - running are the Armor School and the Infantry School , both at Fort Benning , Georgia . Following these basic and advanced training schools , soldiers may opt to continue with their training and apply for an " ASI " which stands for " additional skill identifier " . The ASI allows the army to take a wide ranging MOS and taper it into a more unique MOS . For instance , take a combat medic whose duties are to provide pre - hospital emergency care . With an ASI the medic can receive additional training and become a cardiovascular specialist , a dialysis specialist or even a licensed practical nurse . For officers this training includes pre - commissioning training either at USMA , ROTC , or OCS . After commissioning , officers undergo branch specific training at the Basic Officer Leaders Course , ( formerly called Officer Basic Course ) which varies in time and location based on their future jobs . Further career development is available through the Army Correspondence Course Program . Collective training takes place both at the unit ' s assigned station , but the most intensive collective training takes place at the three combat training centers ( CTC ) ; the National Training Center ( NTC ) at Fort Irwin , California , the Joint Readiness Training Center ( JRTC ) at Fort Polk , Louisiana , and the Joint Multinational Training Center ( JMRC ) at the Hohenfels Training Area in Hohenfels , Germany . ARFORGEN is the Army Force Generation process approved in 2006 to handle the need for continuous replenishment of forces for deployment , at unit level , and for other echelons as required by the mission . The army employs various individual weapons to provide light firepower at short ranges . The most common weapons used by the army are the compact variant of the M16 rifle , the M4 carbine , as well as the 7 . 62x51 mm variant of the FN SCAR for Army Rangers . The primary sidearm in the U . S . Army is the 9 mm M9 pistol . Equipment . Weapons . Many units are supplemented with a variety of specialized weapons , including the M249 SAW ( Squad Automatic Weapon ) , to provide suppressive fire at the fire - team level . Indirect fire is provided by the M203 grenade launcher . The M1014 Joint Service Combat Shotgun or the Mossberg 590 Shotgun are used for door breaching and close - quarters combat . The M14EBR is used by long - range marksmen , and the M107 Long Range Sniper Rifle , the M24 Sniper Weapon System , and the M110 Semi - Automatic Sniper Rifle are used by snipers . Hand grenade s , such as the M67 fragmentation grenade and M18 smoke grenade , are also used . The army employs various crew - served weapons to provide heavy firepower at ranges exceeding that of individual weapons . The M240 is the US Army ' s standard Medium Machine Gun . The M2 heavy machine gun is generally used as a vehicle - mounted machine gun . In the same way , the 40 mm MK 19 grenade machine gun is mainly used by motorized units . The US Army uses three types of mortar for indirect fire support when heavier artillery may not be appropriate or available . The smallest of these is the 60 mm M224 , normally assigned at the infantry company level . At the next higher echelon , infantry battalions are typically supported by a section of 81 mm M252 mortar s . The largest mortar in the army ' s inventory is the 120 mm M120 / M121 , usually employed by mechanized units . Fire support for light infantry units is provided by towed howitzers , including the 105 mm M119A1 and the 155 mm M777 ( which will replace the M198 ) . The US Army utilizes a variety of direct - fire rockets and missiles to provide infantry with an Anti - Armor Capability . The AT4 is an unguided projectile that can destroy armor and bunkers at ranges up to 500 meters . The FIM - 92 Stinger is a shoulder - launched , heat seeking anti - aircraft missile . The FGM - 148 Javelin and BGM - 71 TOW are anti - tank guided missiles . Vehicles . The army ' s most common vehicle is the High Mobility Multipurpose Wheeled Vehicle ( HMMWV ) , commonly called the Humvee , which is capable of serving as a cargo / troop carrier , weapons platform , and ambulance , among many other roles . While they operate a wide variety of combat support vehicles , one of the most common types centers on the family of HEMTT vehicles . The M1A2 Abrams is the army ' s main battle tank , while the M2A3 Bradley is the standard infantry fighting vehicle . Other vehicles include the M3A3 Bradley , the Stryker , and the M113 armored personnel carrier , and multiple types of Mine Resistant Ambush Protected ( MRAP ) vehicles . The Pentagon bought 25 , 000 MRAP vehicles since 2007 in 25 variants through rapid acquisition with no long - term plans for the platforms . The Army plans to divest 7 , 456 vehicles and retain 8 , 585 . Of the total number of vehicles the Army will keep , 5 , 036 will be put in storage , 1 , 073 will be used for training , and the remaining will be spread across the active force . The Oshkosh M - ATV will be kept the most at 5 , 681 vehicles , as it is smaller and lighter than other MRAPs for off - road mobility . The other most retained vehicle will be the Navistar MaxxPro Dash with 2 , 633 vehicles , plus 301 Maxxpro ambulances . Thousands of other MRAPs like the Cougar , BAE Caiman , and larger MaxxPros will be disposed of . The U . S . Army ' s principal artillery weapons are the M109A6 Paladin self - propelled howitzer and the M270 Multiple Launch Rocket System ( MLRS ) , both mounted on tracked platforms and assigned to heavy mechanized units . While the U . S . Army operates a few fixed - wing aircraft , it mainly operates several types of rotary - wing aircraft . These include the AH - 64 Apache attack helicopter , the OH - 58D Kiowa Warrior armed reconnaissance / light attack helicopter , the UH - 60 Black Hawk utility tactical transport helicopter , and the CH - 47 Chinook heavy - lift transport helicopter . Fixed wing aircraft used by the US Army are for non - front line combat and light transport roles . The army relies on the United States Air Force for airlift capabilities . Uniforms . The Army Combat Uniform , or ACU , currently features a digital Universal Camouflage Pattern ( UCP ) and is designed for use in woodland , desert , and urban environments . However , Soldiers operating in Afghanistan are being issued a fire - resistant ACU with the " MultiCam " pattern , officially known as Operation Enduring Freedom Camouflage Pattern or " OCP " . The standard garrison service uniform is known as Army Greens or Class - As and has been worn by all officers and enlisted personnel since its introduction in 1956 when it replaced earlier olive drab ( OD ) and khaki ( and tan worsted or TW ) uniforms worn between the 1950s and 1985 . The Army Blue uniform , dating back to the mid - 19th century , is currently the Army ' s formal dress uniform , but in 2013 , it replaced the Army Green , and in 2014 it will replace the Army White uniform ( a uniform similar to the Army Green uniform , but worn in tropical postings ) and will become the new Army Service Uniform , which will function as both a garrison uniform ( when worn with a white shirt and necktie ) and a dress uniform ( when worn with a white shirt and either a necktie for parades or a bow tie for after six or black tie events ) . Berets . The Army black beret ( having been permanently replaced with the patrol cap ) is no longer worn with the new ACU for garrison duty . After years of complaints that it wasn ' t suited well for most work conditions , Army Chief of Staff General Martin Dempsey eliminated it for wear with the ACU in June 2011 . Soldiers may still wear colored berets who are currently in an airborne unit ( maroon beret ) , Rangers ( tan beret ) , and Special Forces ( green beret ) and may wear it with the Army Service Uniform for non - ceremonial functions . Unit commanders may still direct the wear of patrol caps in these units in training environments or motor pools . Tents . The army has relied heavily on tents to provide the various facilities needed while on deployment . The most common tent uses for the military are as temporary barracks ( sleeping quarters ) , DFAC buildings ( dining facilities ) , forward operating bases ( FOBs ) , after action review ( AAR ) , tactical operations center ( TOC ) , morale , welfare , and recreation ( MWR ) facilities , and security checkpoints . Furthermore , most of these tents are set up and operated through the support of Natick Soldier Systems Center . The U . S . military is beginning to use a more modern tent called the deployable rapid assembly shelter or DRASH . In 2008 , DRASH became part of the Army ' s Standard Integrated Command Post System . 3D printing . In November 2012 the United States Army developed a tactical 3D printing capability to allow it to rapidly manufacture critical components on the battlefield . ( BBC ) Branch establishment . The U . S . Army was officially founded on 14 June 1775 , when the Continental Congress authorized enlistment of riflemen to serve the United Colonies for one year . Each branch of the army has a different branch insignia . Maneuver , Fires , and Effects Branches . Maneuver Ten companies of riflemen were authorized by a resolution of the Continental Congress on 14 June 1775 . However , the oldest Regular Army infantry regiment , the 3rd Infantry Regiment , was constituted on 3 June 1784 , as the First American Regiment . The Armor Branch traces its origin to the Cavalry . A regiment of cavalry was authorized to be raised by the Continental Congress Resolve of 12 December 1776 . Although mounted units were raised at various times after the Revolution , the first in continuous service was the United States Regiment of Dragoons , organized in 1833 . The Tank Service was formed on 5 March 1918 . The Armored Force was formed on 10 July 1940 . Armor became a permanent branch of the army in 1950 . Following the establishment of the U . S . Air Force as a separate service in 1947 , the army began to develop further its own aviation assets ( light planes and rotary wing aircraft ) in support of ground operations . The Korean War gave this drive impetus , and the war in Vietnam saw its fruition , as army aviation units performed a variety of missions , including reconnaissance , transport , and fire support . After the war in Vietnam , the role of armed helicopter s as tank destroyers received new emphasis . In recognition of the growing importance of aviation in army doctrine and operations , aviation became a separate branch on 12 April 1983 . Maneuver Support . Continental Congress authority for a " Chief Engineer for the Army " dates from 16 June 1775 . A corps of engineers for the United States was authorized by the Congress on 11 March 1789 . The Corps of Engineers as it is known today came into being on 16 March 1802 , when the President was authorized to " organize and establish a Corps of Engineers . . . that the said Corps . . . shall be stationed at West Point in the State of New York and shall constitute a Military Academy . " A Corps of Topographical Engineers , authorized on 4 July 1838 , was merged with the Corps of Engineers on March 1863 . The Chemical Warfare Service was established on 28 June 1918 , combining activities that until then had been dispersed among five separate agencies of government . It was made a permanent branch of the Regular Army by the National Defense Act of 1920 . In 1945 , it was re - designated the Chemical Corps . A Provost Marshal General ' s Office and Corps of Military Police were established in 1941 . Prior to that time , except during the Civil War and World War I , there was no regularly appointed Provost Marshal General or regularly constituted Military Police Corps , although a " Provost Marshal " can be found as early as January 1776 , and a " Provost Corps " as early as 1778 . Fires . The Continental Congress unanimously elected Henry Knox " Colonel of the Regiment of Artillery " on 17 November 1775 . The regiment formally entered service on 1 January 1776 . The Air Defense Artillery branch descended from the Anti - Aircraft Artillery ( part of the U . S . Army Coast Artillery Corps ) into a separate branch on 20 June 1968 . Special Operations Forces . The first special forces unit in the Army was formed on 11 June 1952 , when the 10th Special Forces Group was activated at Fort Bragg , North Carolina . A major expansion of special forces occurred during the 1960s , with a total of eighteen groups organized in the Regular Army , Army Reserve , and Army National Guard . As a result of renewed emphasis on special operations in the 1980s , the Special Forces Branch was established as a basic branch of the army effective 9 April 1987 , by General Order No . 35 , 19 June 1987 . Special forces are part of U . S . special operations forces The Civil Affairs / Military Government Branch in the Army Reserve Branch was established as a special branch on 17 August 1955 . Subsequently redesignated the Civil Affairs Branch on 2 October 1955 , it has continued its mission to provide guidance to commanders in a broad spectrum of activities ranging from host - guest relationships to the assumption of executive , legislative , and judicial processes in occupied or liberated areas . Became a basic branch effective 16 October 2006 per General Order 29 , on 12 January 2007 . Established as a basic branch effective 16 October 2006 per General Order 30 , 12 January 2007 . Functional Areas . FA30 - Information Operations FA46 - Public Affairs The Signal Corps was authorized as a separate branch of the army by act of Congress on 3 March 1863 . However , the Signal Corps dates its existence from 21 June 1860 , when Congress authorized the appointment of one signal officer in the army , and a War Department order carried the following assignment : " Signal Department – Assistant Surgeon Albert J . Myer to be Signal Officer , with the rank of Major , 27 June 1860 , to fill an original vacancy . " Signal . FA24 - Telecomm Systems Engineer FA53 - Info Systems Management Military Intelligence . Intelligence has been an essential element of army operations during war as well as during periods of peace . In the past , requirements were met by personnel from the Army Intelligence and Army Security Reserve branches , two - year obligated tour officers , one - tour levies on the various branches , and Regular Army officers in the specialization programs . To meet the army ' s increased requirement for national and tactical intelligence , an Intelligence and Security Branch was established effective 1 July 1962 , by General Order No . 38 , on 3 July 1962 . On 1 July 1967 , the branch was re - designated as Military Intelligence . FA34 - Strategic Intel Foreign Area Officer . FA48 - Foreign Area Officer Functional Areas . FA29 - Electronic Warfare FA40 - Space Ops FA47 - Academy Professor FA49 - Ops Research & Systems Analysis FA50 - Force Management FA52 - Nuclear and Counter Proliferation FA57 - Simulation Ops FA59 - Strategist Logistics . The Quartermaster Corps , originally designated the Quartermaster Department , was established on 16 June 1775 . While numerous additions , deletions , and changes of function have occurred , its basic supply and service support functions have continued in existence . The Ordnance Department was established by act of Congress on 14 May 1812 . During the Revolutionary War , ordnance material was under supervision of the Board of War and Ordnance . Numerous shifts in duties and responsibilities have occurred in the Ordnance Corps since colonial times . It acquired its present designation in 1950 . Ordnance soldiers and officers provide maintenance and ammunition support . The history of the Transportation Corps starts with World War I . Prior to that time , transportation operations were chiefly the responsibility of the Quartermaster General . The Transportation Corps , essentially in its present form , was organized on 31 July 1942 . The Transportation Corps is headquartered at Fort Lee , Virginia . Established by General Order 6 , 27 November 2007 . Consists of multi - functional logistics officers in the rank of captain and above , drawn from the Ordnance , Quartermaster and Transportation Corps . FSD Warrants . Warrant Officers Soldier Support . The post of Adjutant General was established 16 June 1775 , and has been continuously in operation since that time . The Adjutant General ' s Department , by that name , was established by the act of 3 March 1812 , and was re - designated the Adjutant General ' s Corps in 1950 . The Finance Corps is the successor to the old Pay Department , which was created in June 1775 . The Finance Department was created by law on 1 July 1920 . It became the Finance Corps in 1950 . Professional Service Branches The legal origin of the Chaplain Corps is found in a resolution of the Continental Congress , adopted 29 July 1775 , which made provision for the pay of chaplains . The Office of the Chief of Chaplains was created by the National Defense Act of 1920 . The Office of Judge Advocate of the army may be deemed to have been created on 29 July 1775 , and has generally paralleled the origin and development of the American system of military justice . The Judge Advocate General Department , by that name , was established in 1884 . Its present designation as a corps was enacted in 1948 . Acquisition . Acquisition The Army Medical Department and the Medical Corps trace their origins to 27 July 1775 , when the Continental Congress established the army hospital headed by a " Director General and Chief Physician . " Congress provided a medical organization of the army only in time of war or emergency until 1818 , which marked the inception of a permanent and continuous Medical Department . The Army Organization Act of 1950 renamed the Medical Department as the Army Medical Service . In June 1968 , the Army Medical Service was re - designated the Army Medical Department . The Medical Department has the following branches : External links .