Ethos is one of the modes of persuasion espoused by Aristotle. When using ethos to convince people, a person uses their experience and pedigree to establish credibility so that the people they are trying to convince will rest easier knowing that the opinion of the person is from an experienced place.
By telling the runaways of her experiences, Harriet Tubman was gaining credibility by using ethos to convince them. Ideally this would make them listen to her more so as to make it to the North unscathed.
