Timeline 1 or Timeline Zero/Timeline 0 is the original course of events in the Back to the Future trilogy as they took place before time travel was invented. Marty McFly and Doc Brown altered the destinies of nearly everyone with whom they crossed paths:
Clara Clayton was a schoolteacher who was killed in a freak accident in 1885. She had accepted the job of the schoolteacher for the children of Hill Valley, California, but on the day of her arrival, she was killed in a freak accident while driving herself from the train station to her home. George McFly was a timid man who allowed other people to intimidate him and who never accomplished anything of note, and his wife Lorraine Baines McFly led a miserable existence that led to her becoming an alcoholic. Their three children, all of whom lived at home with their parents, appeared to have little potential of having happy lives either. Dave McFly worked at a Burger King, Linda McFly was lonely and despaired of ever having a boyfriend, and Marty did not seem to be bound for anything of importance as his high school tenure was coming to an end. Biff Tannen, who had spent a lifetime bullying other people, had become a supervisor in a job that he was not competent to handle. Doc himself spent life as a recluse, working on various projects without success prior to 1985. After their adventures in the past, the course of events between 1885 and 1985 was altered significantly, and generally to the good.