Who is John Joseph Dobrejcak from Out of This Furnace and what is their importance?

John Joseph Dobrejcak is the son of Mary Kracha and Mike Dobrejcak. He was born in 1903. After his father's death John took various jobs to assist his widowed mother financially. He delivers wallpaper, works in the steel mill, and later obtains a job in construction. After his mother's death, John moves to Detroit for five years before returning to Pennsylvania, where he marries Julie.