Question: When was the lager that used to be brewed in the Latrobe Brewery launched ?

Context paragraphs:
Colorado Native Lager: Colorado Native Lager is a 5.5% abv amber lager introduced in April 2010 by AC Golden Brewing Company, a subsidiary of MillerCoors.  The beer is brewed in a 30-barrel brew house located inside the Coors Brewery in Golden, CO.  Colorado Native is the only lager ever brewed with Rocky Mountain water, Colorado-grown hops, Colorado-grown barley from the San Luis Valley and the oldest strain of brewer’s yeast in Colorado.  The beer is available only in Colorado.

Chopper Heavy: Chopper Heavy, is a 6% Australian Lager that is named after Australian ex-con Mark "Chopper" Reid.  Brewed by Stockdate Brewery, the beer is marketed as the strongest lager] produced in Australia.  The beer is brewed in Rutherglen, Victoria, which was chosen due to the region's link with another infamous character, the bushranger Ned Kelly.

Private Stock (malt liquor): Haffenreffer Private Stock (commonly referred to as P-Stock, The Green Death, Heffy's, Haffen-Wrecker or The Golden Cap) is a brand of malt liquor first brewed in 1953 at the Haffenreffer Brewery in Jamaica Plain, Boston.  In 1965, production of the brand moved to Narragansett Brewing Company in Rhode Island and then to the Falstaff Brewing Company.  It was brewed in Latrobe, Pennsylvania and Utica, New York under license from Haffenreffer & Co.

Iron City Brewing Company: The Iron City Brewing Company (also known as the Pittsburgh Brewing Company) is a beer company that until August 2009 had been located in the Lawrenceville neighborhood of Pittsburgh, Pennsylvania, United States.  On June 11, 2009, it was reported that the brewery was "moving" to Latrobe, Pennsylvania.  That move was recently completed and Iron City is now produced in the Latrobe Brewery that was once used to produce Rolling Rock.

Wrexham Lager: Wrexham Lager is a brewery in Wrexham, north-east Wales, that has produced alcoholic drink for more than 120 years.  A new hi-tech brewery opened in 2011 in the heart of Wrexham, after the original closed in 2000.  The original brewery was demolished between 2002 and 2003.  Only the historic building in which brewing started still remains.  Wrexham lager made a comeback on 29 October 2011 at the Buck House Hotel in Bangor-on-Dee, Wrexham.  The Roberts family who restarted WXM Lager are using the same ingredients as those from which it was originally brewed.

Creemore Springs: Creemore Springs is a brewery in Creemore, Ontario, Canada, which first opened in 1987.  It was founded by John Wiggins and initially brewed mainstream lagers, expanding later into a premium lager and lager brewed with darker malts, brewed with fire under the kettle.  In 2005, it was acquired by Molson, a subsidiary of the seventh largest brewery corporation in the world, Molson Coors Brewing Company.

Wrexham Lager Beer: Wrexham Lager Beer is a brewery and pilsner beer brewed in Wrexham, north-east Wales.  The brewery has existed since 1881 and is reputed to be the first successful lager brewery in the UK.  The original brewery closed in 2000, but re-opened under new owners in 2011 at a different site.  The lager is currently sold in two variants: 'Wrexham Lager' (4.2% ABV) available on draught and 'Wrexham Lager Export' (5% abv) which is only available in bottles.

St. Feuillien Brewery: The St. Feuillien Brewery is a Belgian brewery in Le Roeulx, Belgium, which was founded in 1873.  The brewery, which makes abbey-style beer, has been operated by the Friart family all this time, except for an 11-year hiatus that ended in 1998.  Beers brewed by St. Feuillien include a brown ale and a tripel, the latter of which praised as one of the best tripels available.  A recent addition to their selection is a saison, "which has grown steadily to be up with the best".  In 2016, the brewery launched an IPA called "Belgian Coast".

Dortmunder Export: Dortmunder Export or Dortmunder is a pale lager originally brewed by Dortmunder Union in Dortmund, Germany, in 1873.  A soft-textured beer influenced by the Pilsner lager brewed in Pilsen, it became popular with industrial workers and was responsible for Dortmunder Union becoming Germany's largest brewery and Dortmund having the highest concentration of breweries in Germany.  With the decline of heavy industry in the area, the sales of Dortmunder also declined until, by 1994, the Dortmund Union brewery had shut down, and merged with several other Dortmund breweries to form Brinkhoff's Brewery.

Rolling Rock: Rolling Rock is a 4.4% abv American lager launched in 1939 by Eric John Franco & Co.  Although founded as a local beer in Rhinebeck, New York, it was marketed aggressively and eventually became a national product.  The brand was sold to Anheuser-Busch of St. Louis, Missouri, in mid-2006, which transferred brewing operations to New Jersey.

Supporting paragraphs: Iron City Brewing Company Rolling Rock
Answer: 1939