Background: Henry Jaynes Fonda (May 16, 1905 - August 12, 1982) was an American film and stage actor with a career spanning five decades. Fonda made his mark early as a Broadway actor. He also appeared in 1938 in plays performed in White Plains, New York, with Joan Tompkins. He made his Hollywood debut in 1935, and his career gained momentum after his Academy Award-nominated performance as Tom Joad in The Grapes of Wrath, a 1940 adaptation of John Steinbeck's novel about an Oklahoma family who moved west during the Dust Bowl.
Context: Born in Grand Island, Nebraska in May 1905, Henry Jaynes Fonda was the son of printer William Brace Fonda, and his wife, Herberta (Jaynes). The family moved to Omaha, Nebraska in 1906.  Fonda's patrilineal line originates with an ancestor from Genoa, Italy, who migrated to the Netherlands in the 15th century. In 1642, a branch of the Fonda family immigrated to the Dutch colony of New Netherland on the East Coast of North America. They were among the first Dutch population to settle in what is now upstate New York, establishing the town of Fonda, New York. By 1888, many of their descendants had relocated to Nebraska.  Fonda was brought up as a Christian Scientist, though he was baptized an Episcopalian at St. Stephen's Episcopal Church in Grand Island. He said, "My whole damn family was nice." They were a close family and highly supportive, especially in health matters, as they avoided doctors due to their religion. Despite having a religious background, he later became an agnostic. Fonda was a bashful, short boy who tended to avoid girls, except his sisters, and was a good skater, swimmer, and runner. He worked part-time in his father's print plant and imagined a possible career as a journalist. Later, he worked after school for the phone company. He also enjoyed drawing. Fonda was active in the Boy Scouts of America; Teichmann reports that he reached the rank of Eagle Scout. However, this is denied elsewhere. When he was about 14, his father took him to observe the brutal lynching of Will Brown during the Omaha race riot of 1919. This enraged the young Fonda and he kept a keen awareness of prejudice for the rest of his life. By his senior year in high school, Fonda had grown to more than six feet tall, but remained shy. He attended the University of Minnesota, where he majored in journalism, but he did not graduate. He took a job with the Retail Credit Company.
Question: how old was he when he go into acting?

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