After working as a general assignment reporter for the City News from 1913 to 1917, Stark went over to the Evening Sun in 1917, and to the Times later that same year.
From then until 1951, he reported on business, economic affairs, and labor news for The New York Times, based in that newspaper's Washington bureau.
'"[2][3] In a November 1935 article, "Cars and the Men," Stark reported on automobile workers in Detroit who had lost their jobs owing to increased mechanization.
Stark's Times obituary drew special attention to a series of articles he had written on the battles in the Harlan County, Kentucky, coal fields, and to the "virtual running account" he had provided to Times readers "of the union organizing campaigns, including the rise of the Congress of Industrial Organizations, the sit-down strikes and John L.
At a dinner marking his farewell to Washington, Fred Perkins of the Scripps-Howard Newspaper Alliance said: "We regard Louis Stark as the pioneer of labor reporters.
[3] He also wrote for The Annals of the American Academy of Political and Social Science, Survey Graphic, The Atlantic Monthly, The Yale Review, The Nation's Business, The Outlook, and Current History.
"In these times of strife, when the reason of men is clouded by passion and counsel is darkened by warring opinions," read the citation, "the people of this country are deeply indebted to Mr. Stark for his accurate and fair recording of events in the field of industrial relations.
Never seeking publicity for himself, he has brought distinction to a great newspaper by living up to his ideal of searching for and presenting the whole truth.
They had one son, Arthur, who at the time of Stark's death was executive secretary of the New York State Mediation Board.
[2][14] A memorial article in the New York Times described Stark as a colleague for whom we had a warm affection, Quiet and unassuming, with a kindly sense of humor, he had a devotion to duty that found him writing a final editorial on the very day of his death, even though he had excused himself from coming to the office.