question: When was the lager that used to be brewed in the Latrobe Brewery launched ?
answer: 1939
context: Title: Iron City Brewing Company
  Passage: 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.
  Title: Chopper Heavy
  Passage: 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.
  Title: Creemore Springs
  Passage: 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.
  Title: Dortmunder Export
  Passage: 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.
  Title: Rolling Rock
  Passage: 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.
citations: Iron City Brewing Company Rolling Rock