Question: The company that built the Southern Pacific 2706 went out of business in what year?

Context paragraphs:
Southern Pacific Transportation Company: The Southern Pacific (reporting mark SP) (or Espee from the railroad initials- SP) was a name of multiple American Class I railroads that existed from 1865 to 1998 and all operated in the Western United States.  The names that represented the Southern Pacific were Southern Pacific Railroad, Southern Pacific Company and Southern Pacific Transportation Company.

Sierra Nevada (ferry): Sierra Nevada was a steel-hulled steam-powered passenger ferry operated on San Francisco Bay.  The ferry was built for the Western Pacific Railroad as "Edward T. Jeffery" in 1913 and subsequently renamed "Feather River".  The ferry offered connecting service to San Francisco for Western Pacific train passengers arriving in Oakland, California.  The ferry was sold to Southern Pacific Transportation Company when Western Pacific began using Southern Pacific's Oakland ferry facilities in May, 1933.  Southern Pacific renamed the ferry "Sierra Nevada" and placed it in commuter service between San Francisco and Alameda, California until that route was discontinued in 1939.  The ferry was leased to the Key System for the Golden Gate International Exposition on Treasure Island from 1939 through 1940.  In 1942, the ferry was requisitioned by the federal government to carry shipyard workers from San Francisco to Richmond Yard 1 through World War II.  The Richmond-San Rafael Ferry Company purchased the ferry in 1947 and rebuilt it to carry automobiles between Richmond and San Rafael until the Richmond–San Rafael Bridge opened on 1 September 1956.  The ferry was then towed to San Pedro, Los Angeles where she sank in 1978.

Southern Pacific Railroad of Mexico: The Southern Pacific Railroad of Mexico (reporting mark SPM) was a railroad subsidiary of the Southern Pacific Company in Mexico, operating from Nogales, Sonora, to Mazatlán, Sinaloa.  The Sonora Railway Company began construction in 1880 and opened a link to Nogales in 1882; it was a subsidiary of the American "Sante Fe" line and was subsidized by the Mexican government.  The Southern Pacific bought the Sonora Railway Company in 1898 and operated it as the "Southern Pacific of Mexico" until 1951.

Southern Pacific 4460: Southern Pacific 4460 is the only surviving GS-6 Class steam locomotive.  The GS-6 is a semi-streamlined 4-8-4 Northern type steam locomotive.  GS stands for "Golden State".  The locomotive was built by the Lima Locomotive Works for the Southern Pacific Railroad in 1943.  The GS-6 lacked side skirting and red and orange "Daylight" paint found on previous locomotives of the GS class, and were painted black and silver instead.  This was because the US government controlled locomotive manufacturers during World War II and had turned down Southern Pacific's order of fourteen new Daylight locomotives.  Southern Pacific re-designed the engine for general service and it was finally approved, but the government took four of them and gave them to the smaller and power-starved Western Pacific Railroad.  Their smaller size when compared to previous GS class locomotives and the fact that they were built during World War II earned them the nicknames of "War Babies" and "Baby Daylights".

Santa Fe Pacific Corporation: The Santa Fe Pacific Corporation was formed as the Santa Fe Southern Pacific Corporation on  23, 1983 (1983--) by the merger of Santa Fe Industries, which owned the Atchison, Topeka and Santa Fe Railway, with the Southern Pacific Company, which owned the Southern Pacific Railroad.  After the Interstate Commerce Commission denied their plan to merge their railroads as the Southern Pacific Santa Fe Railroad the holding company name was shortened and the Southern Pacific Railroad sold.

Butte County Railroad: The Butte County Railroad was a 31.5 mi class II railroad that ran from a connection with the Southern Pacific Railroad at Chico, California to the Diamond Match Company lumber mill at Stirling City.  The railroad operated from 1903-1915 and then became the Southern Pacific's Stirling City Branch.  From 1915 until abandonment in the 1970s the line was operated as the Southern Pacific's Stirling City Branch.  The Chico and Northern Railroad was a non-operating subsidiary holding company of the Southern Pacific Railroad that was created to acquire a 32.31 mile line from Chico - Stirling City from the Butte County Railroad.  Upon acquiring the line, Chico & Northern immediately leased the line back to the Butte County Railroad.  The Chico & Northern was dissolved into Southern Pacific in 1912 and never operated any of the line.

SS El Capitan (1917): El Capitan, United States Official Number 285587, was built in 1917 by the Newport News Shipbuilding and Drydock Company at Newport News, Virginia for the Southern Pacific Company's Atlantic Steamship Lines.  In 1915 the line operated from the North River piers 49—52 at the foot of 11th Street in New York to New Orleans under the flag and name of Morgan Line, which combined with the Southern Pacific's rail service from the Pacific Coast was known as the Sunset Gulf Route.  During World War I the ship was purchased from the builder before delivery to the owner by the United States Shipping Board (USSB) which later turned the ship over to the United States Navy which placed her in commission as USS "El Capitan" (ID-1407) from 1918 to 1919.  "El Capitan" was returned to commercial service by the Southern Pacific Company until just before the United States entry into World War II when the United States War Shipping Administration (WSA) acquired the ship, changed her registry to Panama and placed her in operation under its agent, United States Lines.  "El Capitan" was in the Arctic convoy PQ-17 to the Soviet Union when she came under air attack on 9 July 1942, was damaged and abandoned to be sunk by torpedo just after midnight on 10 July.

Southern Pacific class AC-9: The AC-9 was one of two Southern Pacific Railroad's articulated steam locomotive class that ran smokebox forward after 1920.  Twelve AC-9 class locomotives were built by Lima in 1939 and were Southern Pacific's largest and heaviest steam engines, partly a consequence of low quality coal these engines were designed to burn.  The AC-9s were partially streamlined (the only articulated steam engines to be so equipped), having "skyline casings" inspired by Lima's GS series of 4-8-4's, also made for Southern Pacific, and were equipped with coal tenders, unlike the cab forwards.  The wheel arrangement was 2-8-8-4, which was nicknamed "Yellowstone".  Between 1939 and 1952, all the twelve AC-9 engines were in service between Tucumcari, New Mexico, El Paso, Texas, and Tucson, Arizona, where they mainly pulled freight trains and occasionally also passenger trains such as the "Golden State Limited".  In 1952, they were converted to burn oil instead of coal, and moved to Southern Pacific's Modoc line between Sparks, Nevada, and Alturas, California, where they worked in freight service from 1953 until retirement in 1956.

Baldwin Locomotive Works: The Baldwin Locomotive Works was an American builder of railroad locomotives.  It was originally located in Philadelphia, and later moved to nearby Eddystone, Pennsylvania.  Although the company was very successful as the largest producer of steam locomotives, its transition to the production of diesels was far less so.  Later, when the early demand for diesel locomotives to replace steam tapered off, Baldwin could not compete in the marketplace.  It stopped producing locomotives in 1956 and went out of business in 1972, having produced over 70,000 locomotives, the vast majority powered by steam.

Southern Pacific 2706: Southern Pacific 2706 is a 2-8-0 "Consolidation" Class C-8 steam locomotive built by the Baldwin Locomotive Works in 1904 for the Southern Pacific Transportation Company (SP).  It is one of three surviving members of its class, and one of many preserved SP 2-8-0s.

Supporting paragraphs: Southern Pacific 2706 Baldwin Locomotive Works
Answer: 1972