Question: When were cable cars introduced to the U.S. city where tank battalions were located prior to the Korean War?

full_context: Document 1: Miami: Miami's heavy-rail rapid transit system, Metrorail, is an elevated system comprising two lines and 23 stations on a 24.4-mile (39.3 km)-long line. Metrorail connects the urban western suburbs of Hialeah, Medley, and inner-city Miami with suburban The Roads, Coconut Grove, Coral Gables, South Miami and urban Kendall via the central business districts of Miami International Airport, the Civic Center, and Downtown. A free, elevated people mover, Metromover, operates 21 stations on three different lines in greater Downtown Miami, with a station at roughly every two blocks of Downtown and Brickell. Several expansion projects are being funded by a transit development sales tax surcharge throughout Miami-Dade County.
Document 2: Korean War: By August, the KPA had pushed back the ROK Army and the Eighth United States Army to the vicinity of Pusan in southeast Korea. In their southward advance, the KPA purged the Republic of Korea's intelligentsia by killing civil servants and intellectuals. On 20 August, General MacArthur warned North Korean leader Kim Il-sung that he was responsible for the KPA's atrocities. By September, the UN Command controlled the Pusan perimeter, enclosing about 10% of Korea, in a line partially defined by the Nakdong River.
Document 3: Korean War: After the Incheon landing, the 1st Cavalry Division began its northward advance from the Pusan Perimeter. "Task Force Lynch" (after Lieutenant Colonel James H. Lynch), 3rd Battalion, 7th Cavalry Regiment, and two 70th Tank Battalion units (Charlie Company and the Intelligence–Reconnaissance Platoon) effected the "Pusan Perimeter Breakout" through 106.4 miles (171.2 km) of enemy territory to join the 7th Infantry Division at Osan. The X Corps rapidly defeated the KPA defenders around Seoul, thus threatening to trap the main KPA force in Southern Korea.
Document 4: Korean War: By mid-1950, North Korean forces numbered between 150,000 and 200,000 troops, organized into 10 infantry divisions, one tank division, and one air force division, with 210 fighter planes and 280 tanks, who captured scheduled objectives and territory, among them Kaesong, Chuncheon, Uijeongbu, and Ongjin. Their forces included 274 T-34-85 tanks, 200 artillery pieces, 110 attack bombers, some 150 Yak fighter planes, 78 Yak trainers, and 35 reconnaissance aircraft. In addition to the invasion force, the North KPA had 114 fighters, 78 bombers, 105 T-34-85 tanks, and some 30,000 soldiers stationed in reserve in North Korea. Although each navy consisted of only several small warships, the North and South Korean navies fought in the war as sea-borne artillery for their in-country armies.
Document 5: Korean War: Soon after the war began, General MacArthur had begun planning a landing at Incheon, but the Pentagon opposed him. When authorized, he activated a combined U.S. Army and Marine Corps, and ROK Army force. The X Corps, led by General Edward Almond, Commander, consisted of 40,000 men of the 1st Marine Division, the 7th Infantry Division and around 8,600 ROK Army soldiers. By 15 September, the amphibious assault force faced few KPA defenders at Incheon: military intelligence, psychological warfare, guerrilla reconnaissance, and protracted bombardment facilitated a relatively light battle. However, the bombardment destroyed most of the city of Incheon.
Document 6: London: London's first and only cable car, known as the Emirates Air Line, opened in June 2012. Crossing the River Thames, linking Greenwich Peninsula and the Royal Docks in the east of the city, the cable car is integrated with London's Oyster Card ticketing system, although special fares are charged. Costing £60 million to build, it carries over 3,500 passengers every day, although this is very much lower than its capacity. Similar to the Santander Cycles bike hire scheme, the cable car is sponsored in a 10-year deal by the airline Emirates.
Document 7: Korean War: Meanwhile, U.S. garrisons in Japan continually dispatched soldiers and matériel to reinforce defenders in the Pusan Perimeter. Tank battalions deployed to Korea directly from the U.S. mainland from the port of San Francisco to the port of Pusan, the largest Korean port. By late August, the Pusan Perimeter had some 500 medium tanks battle-ready. In early September 1950, ROK Army and UN Command forces outnumbered the KPA 180,000 to 100,000 soldiers. The UN forces, once prepared, counterattacked and broke out of the Pusan Perimeter.
Document 8: London Underground: London Underground A deep - level Central line train at Lancaster Gate bound for Ealing Broadway A larger sub-surface Metropolitan line train at Farringdon bound for Aldgate Overview Locale Greater London, Buckinghamshire, Essex, Hertfordshire Transit type Rapid transit Number of lines 11 Number of stations 270 served (260 owned) Daily ridership 5 million Annual ridership 1.379 billion (2016 / 17) Website London Underground Operation Began operation 10 January 1863; 154 years ago (1863 - 01 - 10) Operator (s) London Underground Limited Reporting marks LT (National Rail) Technical System length 402 km (250 mi) Track gauge 1,435 mm (4 ft 8 ⁄ in) standard gauge Electrification 630 V DC fourth rail Average speed 33 km / h (21 mph)
Document 9: Fisherman's Wharf, San Francisco: Fisherman's Wharf is a neighborhood and popular tourist attraction in San Francisco, California. It roughly encompasses the northern waterfront area of San Francisco from Ghirardelli Square or Van Ness Avenue east to Pier 35 or Kearny Street. The F Market streetcar runs through the area, the Powell-Hyde cable car lines runs to Aquatic Park, at the edge of Fisherman's Wharf, and the Powell-Mason cable car line runs a few blocks away.
Document 10: Korean War: In the resulting Battle of Pusan Perimeter (August–September 1950), the U.S. Army withstood KPA attacks meant to capture the city at the Naktong Bulge, P'ohang-dong, and Taegu. The United States Air Force (USAF) interrupted KPA logistics with 40 daily ground support sorties that destroyed 32 bridges, halting most daytime road and rail traffic. KPA forces were forced to hide in tunnels by day and move only at night. To deny matériel to the KPA, the USAF destroyed logistics depots, petroleum refineries, and harbors, while the U.S. Navy air forces attacked transport hubs. Consequently, the over-extended KPA could not be supplied throughout the south. On 27 August, 67th Fighter Squadron aircraft mistakenly attacked facilities in Chinese territory and the Soviet Union called the UN Security Council's attention to China's complaint about the incident. The US proposed that a commission of India and Sweden determine what the US should pay in compensation but the Soviets vetoed the US proposal.
Document 11: United States in the Korean War: The first battle the Americans entered in the Korean War was the Battle of Osan, where about four hundred strong landed in Pusan airport on the first of July. The American troops were sent off to Taejon the next morning where Major General John H. Church the head of U.S. field headquarters was confident in the US troop's strengths to push back the North Koreans. On July fifth the troops were finally put to the test when North Korean tanks crept towards Osan. The four hundred infantryman of the U.S. also called Task Force Smith opened fire on the North Koreans at 8: 16 am. Only four of the North Korean tanks were destroyed and twenty - nine kept moving forward breaking the US line. At the end of the battle only two more North Korean Tanks and two regiments of North Korean infantry were destroyed. The US had lost the battle, revealing that the mere sight of US troops would not reverse the military balance in Korea. By early August, the North Korean troops had pushed back the US and South Korean troops all the way to Naktong River, which is located about thirty miles from Pusan. The two weeks of fighting following this resulted in the most casualties of US troops than any other equivalent period of this war. However, during this time the US pushed supplies and personnel to Korea and by the end of July South Koreans and US troops outnumbered the North Koreans, although the North had pushed back the US and South by an amazing amount the North had suffered over fifty thousand casualties. Also because North Koreas supply lines were so lengthy and with the US in control of the water and air replenishing there losses were slow.
Document 12: San Diego: San Diego is served by the San Diego Trolley light rail system, by the SDMTS bus system, and by Coaster and Amtrak Pacific Surfliner commuter rail; northern San Diego county is also served by the Sprinter light rail line. The Trolley primarily serves downtown and surrounding urban communities, Mission Valley, east county, and coastal south bay. A planned Mid-Coast extension of the Trolley will operate from Old Town to University City and the University of California, San Diego along the I-5 Freeway, with planned operation by 2018. The Amtrak and Coaster trains currently run along the coastline and connect San Diego with Los Angeles, Orange County, Riverside, San Bernardino, and Ventura via Metrolink and the Pacific Surfliner. There are two Amtrak stations in San Diego, in Old Town and the Santa Fe Depot downtown. San Diego transit information about public transportation and commuting is available on the Web and by dialing "511" from any phone in the area.
Document 13: San Francisco cable car system: San Francisco cable car system Cable car on Powell Street Overview Owner San Francisco Municipal Transportation Agency Area served Chinatown, Financial District, Fisherman's Wharf, Nob Hill, Russian Hill, Union Square Locale San Francisco Transit type Cable car Number of lines Line number 59 Powell - Mason 60 Powell - Hyde 61 California St. Number of stations 62 Daily ridership 20,100 (2014) Annual ridership 7,409,400 (2014) Headquarters San Francisco Cable Car Museum Website sfmta.com Operation Began operation California St. line: 1878 Powell - Mason line: 1888 Powell - Hyde line: 1957 Operator (s) San Francisco Municipal Railway Reporting marks MUNI Character Street running with some reserved right - of - ways Number of vehicles California St. line: 12 double - ended cars Powell - Mason / Hyde lines: 28 single - ended cars Train length 1 grip car Technical System length California St. line: 1.4 mi (2.3 km) Powell - Mason line: 1.6 mi (2.6 km) Powell - Hyde line: 2.1 mi (3.4 km) No. of tracks Track gauge 3 ft 6 in (1,067 mm) Top speed 9.5 mph (15.3 km / h) hide System map
Document 14: Portland, Oregon: Car sharing through Zipcar, Car2Go, Getaround, and Uhaul Car Share is available to residents of the city and some inner suburbs. Portland has a commuter aerial cableway, the Portland Aerial Tram, which connects the South Waterfront district on the Willamette River to the Oregon Health & Science University campus on Marquam Hill above.
Document 15: List of Barcelona Metro stations: Lines L1, L2, L3, L4, L5, L9, L10, L11 and the Funicular de Montjuïc are administered by Transports Metropolitans de Barcelona (TMB), the city's transit company. Lines L6, L7, L8 and L12 are in origin commuter train services with extended frequency and integrated into the metro network, numbered as such, and run by the public Ferrocarrils de la Generalitat de Catalunya (FGC), which belongs to the Catalan government or Generalitat de Catalunya.
ground_truth: 1878
sub_queries: Where in the United States was the tank battalion located? Answer: San Francisco
when did cable cars start in San Francisco Answer: 1878