The Franklin Project by Ben DeSantis

After losing his job, newlywed Ethan Pope thought things were not going his way. But after he won the national contest from the post office, Ethan discovered his longtime postman, Henry, was part of a secret division within the postal system, which was created by Benjamin Franklin. Henry informs Ethan that he played a vital role in influencing Dr. Franklin to be in favor of American independence, the only problem was, he was going to have to take a one-way trip back in time to convince him again.