The First Lady calls Epping to thank him for saving President Kennedy. Not just for herself, but for his children.
Jake's first time travel attempt allows him to save all but one of the Dunning children. When he returns and calls the now living Dunning sister, she recognizes him as their savior, but then screams at him for not saving Harry from getting killed in Vietnam. Jake can only drop the phone in despair.
Jake making the decision to reset time again, making it so that he never met Sadie in her lifetime.