Explore the role of the President of the United States with the Mark Twain U.S. Presidents eBook!• This 128-page downloadable book for grades 5 and up provides biographical sketches on all the people who have served as a U.S. President.• Presidential biographies include the person's early years, how they became president, what happened during their terms in office, and how they spent their years after leaving office. • Each lesson includes a reading selection, a recalling key details page, and e