Question: In what US city is the Sixth Army headquartered?

full_context: Document 1: United States Army Alaska: United States Army Alaska (USARAK or "America's Arctic Warriors") is a military command of the United States Army located in the U.S. state of Alaska. A subordinate command of the United States Army Pacific, USARAK is the ground element of the Alaskan Command. USARAK is headquartered at Fort Richardson and commanded by a major general.
Document 2: Fort Huachuca: Fort Huachuca is a United States Army installation, established 3 March 1877 as Camp Huachuca. The garrison is now under the command of the United States Army Installation Management Command. It is located in Cochise County, in southeast Arizona, about 15 mi north of the border with Mexico and at the northern end of the Huachuca Mountains, next to the town of Sierra Vista. From 1913 to 1933 the fort was the base for the "Buffalo Soldiers" of the 10th Cavalry Regiment. During the buildup of World War II, the fort had quarters for more than 25,000 male soldiers and hundreds of WACs. In the 2010 census, Fort Huachuca had a population of about 6,500 active duty soldiers, 7,400 military family members and 5,000 civilian employees. Fort Huachuca has over 18,000 people on post during the peak working hours of 0700 and 1600 on week days, making it one of the busiest Army installations.
Document 3: Sixth United States Army: Sixth Army is a field army of the United States Army. The Army service component command of United States Southern Command, its area of responsibility includes 31 countries and 15 areas of special sovereignty in Central and South America and the Caribbean. It is headquartered at Fort Sam Houston.
Document 4: Fort Sam Houston: Fort Sam Houston is a U.S. Army post in San Antonio, Texas.
Document 5: Battle of San Jacinto: The Battle of San Jacinto, fought on April 21, 1836, in present-day Harris County, Texas, was the decisive battle of the Texas Revolution. Led by General Sam Houston, the Texian Army engaged and defeated General Antonio López de Santa Anna's Mexican army in a fight that lasted just 18 minutes.
Document 6: Alamo Mission in San Antonio: The Alamo Mission in San Antonio is commonly called The Alamo and was originally known as "Misión San Antonio de Valero". It was founded in the 18th century as a Roman Catholic mission and fortress compound, and today is part of the San Antonio Missions World Heritage Site in San Antonio, Texas, United States. It was the site of the Battle of the Alamo in 1836, and is now a museum in the Alamo Plaza Historic District.
Document 7: Sixth United States Army Group: The Sixth United States Army Group was an Allied Army Group that fought in the European Theater of Operations during World War II. Made up of field armies from both the United States Army and the French Army, it fought in France, Germany, Austria, and, briefly, Italy. Also referred to as the Southern Group of Armies, it was established in July 1944 and commanded throughout its duration by General Jacob L. Devers.
Document 8: United States Pacific Command: United States Pacific Command (USPACOM) is a unified combatant command of the United States Armed Forces responsible for the Indo-Asia-Pacific region. It is the oldest and largest of the unified combatant commands. Its commander, the senior U.S. military officer in the Pacific, is responsible for military operations in an area which encompasses more than 100 e6sqmi , or roughly 52 percent of the Earth’s surface, stretching from the waters off the west coast of the United States to the west coast of India, and from the Arctic to the Antarctic. The Commander reports to the President of the United States through the Secretary of Defense and is supported by Service component and subordinate unified commands, including U.S. Army Pacific, U.S. Pacific Fleet, U.S. Pacific Air Forces, U.S. Marine Forces Pacific, U.S. Forces Japan, U.S. Forces Korea, Special Operations Command Korea, and Special Operations Command Pacific. USPACOM also has three direct reporting units (DRUs), including Daniel K. Inouye Asia-Pacific Center for Security Studies, U.S. Pacific Command Joint Intelligence Operations Center, Center for Excellence in Disaster Management and Humanitarian Assistance; and a Standing Joint Task Force, Joint Interagency Task Force West. The USPACOM headquarters building, the Nimitz-MacArthur Pacific Command Center, is located on Camp H.M. Smith, Hawaii.
Document 9: Fort Benning: Fort Benning is a United States Army base straddling the Alabama-Georgia border next to Columbus, Georgia. Fort Benning supports more than 120,000 active-duty military, family members, reserve component soldiers, retirees, and civilian employees on a daily basis. It is a power projection platform, and possesses the capability to deploy combat-ready forces by air, rail, and highway. Fort Benning is the home of the United States Army Maneuver Center of Excellence, the United States Army Armor School, United States Army Infantry School, the Western Hemisphere Institute for Security Cooperation (formerly known as the School of the Americas), elements of the 75th Ranger Regiment (United States), 3rd Brigade – 3rd Infantry Division, and many other additional tenant units.
Document 10: San Antonio Missions National Historical Park: San Antonio Missions National Historical Park is a National Historical Park and part of a UNESCO World Heritage Site preserving four of the five Spanish frontier missions in San Antonio, Texas, USA. These outposts were established by Catholic religious orders to spread Christianity among the local natives. These missions formed part of a colonization system that stretched across the Spanish Southwest in the 17th, 18th, and 19th centuries.
Document 11: United States Army Reserve Command: United States Army Reserve Command (USARC) commands all United States Army Reserve units. USARC is responsible for the staffing, training, management and deployment of its units to ensure their readiness for Army missions. The Army Reserve which consists of three main categories of units.
Document 12: Dwight D. Eisenhower Army Medical Center: The Dwight D. Eisenhower Army Medical Center (EAMC) is a 93-bed medical treatment facility located on Fort Gordon, Ga., located near Augusta, Georgia that previously served as the headquarters of the Army's Southeast Regional Medical Command (SERMC). SERMC oversaw the Army's hospitals and clinics within the southeastern United States and Puerto Rico. SERMC was renamed Southern Regional Medical Command (SRMC) and was relocated to San Antonio in 2009.
Document 13: Sam's Army: Sam's Army, now defunct, was an unofficial supporters' group for the United States men's national soccer team. The name of the group derives from Uncle Sam, a national personification of the United States, and the Scottish supporters' group the Tartan Army. Sam's Army debuted at a 1995 U.S. Cup game following the 1994 FIFA World Cup. In 2010 there were more than 14,000 members of Sam's Army, and the organization reported having members around the world. Sam's Army was known for wearing all red and usually standing behind a goal during United States national team matches. George Vecsey of "The New York Times" described Sam's Army as, "a relative handful of goofy characters in red outfits... who follow the American team around the globe."
Document 14: 2009 Fort Hood shooting: On November 5, 2009, a mass shooting took place at Fort Hood, near Killeen, Texas. Nidal Hasan, a U.S. Army major and psychiatrist, fatally shot 13 people and injured more than 30 others. The shooting was the worst mass shooting on an American military base.
Document 15: United States Fleet Forces Command: The United States Fleet Forces Command (USFLTFORCOM) is a service component command of the United States Navy that provides naval forces to a wide variety of U.S. forces. The naval resources may be allocated to Combatant Commanders such as United States Northern Command (USNORTHCOM) under the authority of the Secretary of Defense. Originally formed as United States Atlantic Fleet (USLANTFLT) in 1906, it has been an integral part of the defense of the United States of America since the early 20th century. In 2002, the Fleet comprised over 118,000 Navy and Marine Corps personnel serving on 186 ships and in 1,300 aircraft, with an area of responsibility ranging over most of the Atlantic Ocean from the North Pole to the South Pole, the Caribbean Sea, Gulf of Mexico, and the waters of the Pacific Ocean along the coasts of Central and South America (as far west as the Galapagos Islands). The command is based at Naval Support Activity Hampton Roads in Norfolk, Virginia and is the Navy's service component to U.S. Northern Command and is a supporting command under the U.S. Strategic Command.
ground_truth: San Antonio, Texas.