Born in Spokane, Washington, Tunberg's earliest writings included short stories, and a novel entitled While the Crowd Cheers, which was published in 1935 by the Macaulay Company.
Among his credits are My Gal Sal (1942), Standing Room Only (1944), Kitty (1945) both with Paulette Goddard, Because You're Mine (1952), Valley of the Kings (1954), Beau Brummell (1954), The Seventh Sin (1957), Count Your Blessings (1958), Libel (1959).
As noted in many contemporary sources, in addition to Tunberg, who had written the first script for the project more than five years before the start of principal photography, Christopher Fry and Gore Vidal contributed to the screenplay during filming.
In response to Wyler's public outcries against their ruling, the WGA took out trade paper ads on November 20, 1959 in which they issued a statement reading, in part, "the unanimous decision of the three judges was that the sole screenplay credit was awarded to Karl Tunberg...The record shows the following: 1.
In the early 1970s Karl Tunberg began writing segments for television series, but he used to tell family and friends that his favorite medium was always the large-screen motion picture.