Who does Benjamin Franklin hope to help by writing his autobiography?

At the beginning of his autobiography, Benjamin Franklin addresses his son, William, who was then the Governor of New Jersey. Franklin tells him that just as he, Benjamin, was interested in learning more about his ancestors in England, he imagines that his son might be interested in learning more about his father's life. Franklin also hopes to help his "posterity," or descendants, by telling them about his rise from his humble and obscure origins to his achievement of success and renown. He thinks that by reading his book, his descendants can imitate some of what has made him happy and successful. Franklin's book, which remained unfinished at the time of his death in 1790, was written over the course of several years (starting in 1771), though he stated at the beginning of his book that he hoped to write down some anecdotes over the course of a week.