He was born in Denver, Colorado, in 1906, the son of Jewish immigrants. He was born at a weight of less than four pounds. Jacob was small for his age, until he reached his seventh birthday. By the time was ten, he was over six feet tall. His family lived in El Paso Texas at this time and the locals nicknamed him "Pecos Bill" (a title he used for over twenty years.)
Because of his intimidating height, he would avoid people by walking the alleys on his way to school so he could hide if he encountered anyone (for fear of frightening them).
When he was thirteen he and his father made a trip to Los Angeles. Over seven feet tall at the time, he attracted the attention of Century Comedies, a motion picture production company. Jerry Ash and Zion Meyers offered him a job in the movies. He convinced his father that this was a good opportunity, and he was allowed to stay. Jacob took the screen name Jack Earle when he started working in the silent film industry, there he appeared in many movies.
He appeared in films like Hansel and Gretel in 1923 and Jack & the Beanstalk in 1924.
Over the next few years he found himself busy in the movie making business, and going to school.
His movie career came to an end when during filming he fell from the scaffolding. He broke his nose and was hospitalized. While in the hospital, his eyesight became blurry and within days he lost his sight completely. As his doctor examined him, he found a pituitary tumor. The tumor had pushed up against his optic nerve during the fall. For the next four months, Jack underwent X-ray treatments. His eyesight returned, although it has been speculated that the treatment may have stopped his growth. At the time of his hospitalization he was seven feet six inches tall.
While touring El Paso, Texas, Ringling Bros. offered "Jack" a one year contact, which turned into fourteen years of employment. During his time with the Ringling Bros., Jack met most of the giants who lived during his lifetime.
He stayed with the circus until the late thirties or early forties. He was tired of the routine and decided to leave the business. Undecided about his future, he decided to lay the "Pecos Bill" persona to rest and he returned to California.
He went on to become a Roma Wine Company salesman, working his way up to becoming their public relations specialist.
In addition, Earle was a talented artist and worked in a variety of media, including painting, sculpture, photography, and poetry. He was published in a book entitled The Long Shadows, and on November 4, 1950, the Saturday Evening Post ran an article titled Life of Giant Jack Earle.