{{short description|US Army Reserve unit based in Puerto Rico and the US Virgin Islands}} {{Infobox military unit | unit_name = 1st Mission Support Command | image = 1st_Mission_Support_Command,_US_Army_(shoulder_sleeve_insignia).svg | image_size = 150 | caption = Shoulder sleeve insignia | dates = 7 February 2008 - present | country = {{flagicon|US}} United States | branch = 25px United States Army Reserve | specialization = Sustainment | type = Support Command | role = | size = | command_structure = 25px United States Army Reserve Command | garrison = Fort Buchanan, Puerto Rico | garrison_label = Garrison/HQ | equipment = | equipment_label = | nickname = | patron = | motto = "Garita Warriors! Always First!" | colors = | colors_label = Transportation Corps colors | march = | mascot = | battles = | anniversaries = | decorations = | battle_honours = <!-- Commanders --> | commander1 = Brig. Gen. Christopher Creaghe | current_commander = Brig. Gen. Carlos E. Gorbea | current_commander_label = Commanding General | ceremonial_chief = CSM Lorraine C. Smith | ceremonial_chief_label = Command Sergeant Major | colonel_of_the_regiment = | colonel_of_the_regiment_label = | notable_commanders = <!-- Insignia --> | identification_symbol = | identification_symbol_label = Distinctive unit insignia | identification_symbol_2 = | identification_symbol_2_label = }}
The '''1st Mission Support Command''' ('''1st MSC''') is a United States Army Reserve command providing support to military units based in Puerto Rico and the US Virgin Islands. Headquartered at Fort Buchanan within the metropolitan area of the Puerto Rico's capital San Juan, the command consists of 54 units and fields 4,200 soldiers.<ref>{{Cite web|url=https://www.usar.army.mil/1stMSC/|title = 1st MSC}}</ref>
== History == In 1922 the 373rd Infantry was moved to the Organized Reserve and was headquartered in San Juan, Puerto Rico.
"The Puerto Rican Department was established by the War Department in May 1939 to assume the responsibility, previously that of the Second Corps Area, for the defense of the Puerto Rico area and for conducting Corps Area administrative, intelligence, training, supply, and other Army services, including the administration of National Guard affairs, in Puerto Rico.<ref>[https://www.ibiblio.org/hyperwar/ATO/FRWW2-II/FRWW2-4.html Federal Records of World War II: Volume II Military Records: Part Four: Theatres of Operation [1083] ]</ref> In May 1941 the Department was made a regional defense command under the newly established Caribbean Defense Command, and for tactical purposes its territory was regarded as the Puerto Rican Sector. Army forces in the Department were under the operational control of the Navy's Caribbean Sea Frontier. On June 1, 1943, the Puerto Rican Department was renamed the Antilles Department, and its territorial limits were extended to include the bases in the British West Indies and British Guiana leased by the United States from the United Kingdom in September 1940.<ref>See Destroyers-for-bases deal</ref> The area of these bases was collectively called, for tactical purposes, the Trinidad Sector, and in January 1944 it was extended to include the Aruba-Curaçao subsector and territory in Venezuela west of Caracas. The Headquarters of the two successive Departments was at San Juan, P.R."
"The Department's major combat organizations in Puerto Rico were its Coast Artillery troop units, reorganized as the Antilles Coast Artillery Command, and its air defense and air service organization, which developed into the Antilles Air Command (AAC). In October 1943 the AAC withdrew from tactical operations and became essentially an air training command."
"Outside of Puerto Rico, the Antilles Department's major forces at the island bases consisted of garrison forces, which were trained for ground defense operations, if necessary; construction and maintenance troops; and other service troops. These forces were under the general regional supervision of the Trinidad Sector and Base Command, known as the Trinidad Base Command after May 1, 1944. The other island forces were the Antigua Base Command, the Aruba Defense Command, United States Army Forces, Bahamas, the British Guiana Base Command, the Curaçao Defense Command, United States Army Forces, French Guiana, United States Army Forces, Jamaica and (later) the Jamaica Base Command, the Santa Lucia Base Command, and United States Army Forces, Surinam."
"By October 1943 combat operations in the Antilles area came to a successful close, and the Antilles Department's activities during the remainder of the war were redirected toward tactical air and ground training." In 1948 the Antilles Department was renamed the United States Army Forces, Antilles."
The Puerto Rican Department first wore the Garita Patch in 1942.<ref>{{Cite web |date=September 9, 1942 |title=1ST MISSION SUPPORT COMMAND |url=https://tioh.army.mil/Catalog/Heraldry.aspx?HeraldryId=7085&CategoryId=3974&grp=2&menu=Uniformed%20Services&ps=24&p=0 |access-date=July 7, 2025 |website=US Army Institute of Heraldry}}</ref> It was redesignated for the Antilles Department in 1944 and in 1948, the unit was redesignated U.S. Army Forces, Antilles.
Brigadier General Edwin L. Sibert, Commander, United States Army Forces, Antilles, represented the United States Army at the 100th anniversary of the raising of the Flag of Cuba in June 1950, during the presidency of Carlos Prío Socarrás in Cuba.<ref>{{cite web |url=https://www.latinamericanstudies.org/embassy/R31-677-3-24-1950.pdf |title=Cuban Investigation for Representatives of the United States Armed Forces to Participate in the Celebration of the First Centennial of the Cuban Flag |date=March 24, 1950 |location=Habana}}</ref> thumb|right|Senior U.S. Department of Defense officials and officers witness Operation Portrex maneuvers on Puerto Rico, 8 March 1950. Sibert appears to have served as Opposing Force commander. In 1973, the Support Group was placed directly under First United States Army. By 1974, the 166th Support Group was given full mission control of all United States Army Reserve units in Puerto Rico and the United States Virgin Islands and assumed the mission and functions of a major U.S. Army Reserve Command, under First U.S. Army.
The insignia was reassigned to the 7581st USAR Garrison in 1981 and redesignated to the U.S. Army Reserve Forces Puerto Rico in 1990. The lineage continued through the 65th U.S. Army Reserve Command in 1992, and again to the 65th Regional Support Command in 1998. The 65th RSC became the 65th Regional Readiness Command in 2003. The lineage passed to the 166th Support Group in 2007, and finally the 1st Support Command on 7 February 2008.<ref name="U.S. Army Reserve 2002">{{cite web | title=Caribbean Geographical Command is a reality | website=U.S. Army Reserve | date=2002-07-11 | url=https://www.usar.army.mil/News/Article/1709779/caribbean-geographical-command-is-a-reality/ | access-date=2021-02-06}}</ref>
Today the 1st Mission Support Command continues to wear the Garita Patch.
== Organization == The 1st Mission Support Command is a subordinate geographic command of the United States Army Reserve Command responsible for reserve units in Puerto Rico and the US Virgin Islands. As of January 2026 the command consists of the following units:<ref name="Our units">{{cite web |title=Our units |url=https://www.usar.army.mil/Commands/Geographic/1st-MSC/1st-MSC-Units/ |publisher=1st Mission Support Command |access-date=31 December 2025}}</ref> {{tree list}} * 27px '''1st Mission Support Command''', at Fort Buchanan (PR)<ref name="Our units"/><ref name="Puerto Rico">{{cite web |title=Puerto Rico units |url=https://www.usar.army.mil/Featured/Ambassador-Program/Find-an-Ambassador/Puerto-Rico/ |publisher=US Army Reserve |access-date=2 January 2026}}</ref> ** Headquarters and Headquarters Company, at Fort Buchanan (PR)<ref name="Puerto Rico"/> ** 363rd Public Affairs Detachment, at Fort Buchanan (PR)<ref name="Puerto Rico"/> ** 27px '''166th Regional Support Group''', at Fort Buchanan (PR)<ref name="Our units"/><ref name="Puerto Rico"/> *** Headquarters and Headquarters Company, at Fort Buchanan (PR)<ref name="Puerto Rico"/> *** '''346th Transportation Battalion (Motor)''', at Roosevelt Roads Naval Station (PR)<ref name="Our units"/><ref name="Puerto Rico"/> **** Headquarters and Headquarters Detachment, 346th Transportation Battalion (Motor), at Roosevelt Roads Naval Station (PR)<ref name="Puerto Rico"/> **** 204th Transportation Medium Truck Company (POL, 5K GAL) (Echelon Above Brigade Linehaul), in Juana Díaz (PR)<ref name="Puerto Rico"/> **** 273rd Transportation Detachment (Movement Control Team), at Roosevelt Roads Naval Station (PR)<ref name="Puerto Rico"/> **** 390th Transportation Company (Seaport Operations), at Roosevelt Roads Naval Station (PR)<ref name="Puerto Rico"/> **** 420th Quartermaster Company (Supply), in Puerto Nuevo (PR)<ref name="Puerto Rico"/> **** 432nd Transportation Medium Truck Company (Cargo) (Echelon Above Brigade Linehaul), at Roosevelt Roads Naval Station (PR)<ref name="Puerto Rico"/> **** 512th Transportation Detachment (Movement Control Team), in Saint Thomas (US Virgin Islands)<ref>{{cite web |title= Overseas units |url=https://www.usar.army.mil/Locate-a-Reserve-Unit/Reserve-Unit-Locations/ |publisher=US Army Reserve |access-date=2 January 2026}}</ref> **** 597th Quartermaster Company (Field Service) (Modular), in Puerto Nuevo (PR)<ref name="Puerto Rico"/> **** 941st Quartermaster Company (Petroleum Support), in Salinas (PR)<ref name="Puerto Rico"/> **** 969th Quartermaster Detachment (Petroleum Liaison Team), in Salinas (PR)<ref name="Puerto Rico"/> **** 973rd Quartermaster Company (Water Purification and Distribution), in Ceiba (PR)<ref name="Puerto Rico"/> *** '''393rd Combat Sustainment Support Battalion''', at Fort Buchanan (PR)<ref name="Our units"/><ref name="Puerto Rico"/> **** Headquarters and Headquarters Company, 393rd Combat Sustainment Support Battalion, at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 215th Military Police Detachment (Law Enforcement), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 268th Transportation Company (Inland Cargo Transfer Company — ICTC), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 271st Personnel Company (Human Resources), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 301st Military Police Company (General Support), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 389th Financial Management Support Detachment, at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 398th Financial Management Support Detachment, at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 413th Financial Management Support Detachment, at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 430th Quartermaster Company (Field Service) (Modular), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 613th Military Police Company (Detention), at Juana Díaz (PR)<ref name="Puerto Rico"/> **** 764th Quartermaster Detachment (Field Feeding Team), in Ceiba (PR)<ref name="Puerto Rico"/> **** 765th Quartermaster Detachment (Field Feeding Team), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 766th Quartermaster Detachment (Field Feeding Team), in Puerto Nuevo (PR)<ref name="Puerto Rico"/> ** 27px '''210th Regional Support Group''', in Aguadilla (PR)<ref name="Our units"/><ref name="Puerto Rico"/> *** Headquarters and Headquarters Company, in Aguadilla (PR)<ref name="Puerto Rico"/> *** '''35th Expeditionary Signal Battalion''', in Juana Díaz (PR)<ref name="Our units"/><ref name="Puerto Rico"/> **** Headquarters and Headquarters Company, in Juana Díaz (PR)<ref name="Puerto Rico"/> **** Alpha Company, 35th Expeditionary Signal Battalion, in Yauco (PR)<ref name="Puerto Rico"/> **** Bravo Company, 35th Expeditionary Signal Battalion, in Aguadilla (PR)<ref name="Puerto Rico"/> **** Charlie Company, 35th Expeditionary Signal Battalion, in Puerto Nuevo (PR)<ref name="Puerto Rico"/> *** '''77th Combat Sustainment Support Battalion''', in Aguadilla (PR)<ref name="Our units"/><ref name="Puerto Rico"/> **** Headquarters and Headquarters Company, 77th Combat Sustainment Support Battalion, in Aguadilla (PR)<ref name="Puerto Rico"/> **** 246th Quartermaster Company (Mortuary Affairs), in Mayagüez (PR)<ref name="Puerto Rico"/> **** 266th Ordnance Company (Ammo) (Modular), in Aguadilla (PR)<ref name="Puerto Rico"/> **** 276th Ordnance Company (Support Maintenance), at Fort Allen (PR)<ref name="Puerto Rico"/> **** 311th Quartermaster Company (Mortuary Affairs), in Aguadilla (PR)<ref name="Puerto Rico"/> *** '''448th Engineer Battalion''', at Fort Buchanan (PR)<ref name="Our units"/><ref name="Puerto Rico"/> **** Headquarters and Headquarters Company, 448th Engineer Battalion, at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** Forward Support Company, 448th Engineer Battalion, at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 471st Engineer Company (Vertical Construction Company — VCC), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 475th Engineer Company (Engineer Construction Company — ECC), in Ponce (PR)<ref name="Puerto Rico"/> **** 602nd Engineer Detachment (Engineer Facility Detachment — EFD), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 603rd Engineer Detachment (Concrete Section), at Fort Buchanan (PR)<ref name="Puerto Rico"/> **** 756th Engineer Company (Engineer Construction Company — ECC), at Roosevelt Roads Naval Station (PR)<ref name="Puerto Rico"/> ** 27px '''Caribbean Readiness Group''', at Fort Buchanan (PR)<ref name="Puerto Rico"/><ref name="Cuebas">{{cite web |last1=Lt. Col. Carlos M. Cuebas |title=Caribbean Geographical Command is a reality |url=https://www.usar.army.mil/News/News-Display/Article/1709779/caribbean-geographical-command-is-a-reality/ |publisher=1st Mission Support Command |access-date=4 January 2026}}</ref> *** '''49th Medical Battalion (Multifunctional)''', in Puerto Nuevo (PR)<ref name="Our units"/><ref name="Puerto Rico"/><ref name="Cuebas"/> **** Headquarters and Headquarters Detachment, in Puerto Nuevo (PR)<ref name="Puerto Rico"/> **** 334th Medical Detachment Team (Optometry), in Puerto Nuevo (PR)<ref name="Puerto Rico"/> **** 335th Medical Company (Area Support), in Puerto Nuevo (PR)<ref name="Puerto Rico"/> **** 407th Medical Company (Ground Ambulance), in Puerto Nuevo (PR)<ref name="Puerto Rico"/> *** '''1st Battalion, 333rd Regiment (Multifunctional Training)''', at Fort Buchanan (PR)<ref name="Puerto Rico"/><ref name="Cuebas"/> *** '''2nd Battalion, 348th Regiment (Training Support)''', at Fort Buchanan (PR)<ref name="Puerto Rico"/><ref name="Cuebas"/> *** '''1st Battalion, 389th Regiment (Basic Combat Training)''', at Fort Buchanan (PR)<ref name="Puerto Rico"/><ref name="Cuebas"/> *** '''402nd Civil Affairs Battalion''', at Fort Buchanan (PR)<ref name="Puerto Rico"/><ref name="Cuebas"/> {{tree list/end}}
== References == {{reflist}}
Category:Support Commands of the United States Army Category:Military units and formations of the United States Army Reserve Category:Military units and formations in Puerto Rico