(HuffPo) — At age 8, Maria Keller, of Orono, Minn., learned that not all children own a book. Determined to do something about it, she declared she would donate 1 million books to kids in need by the time she turned 18. Keller not only reached her goal this week, she did it five years early. On Tuesday, a children’s book publisher in Mankato, Minn., gave the 13-year-old philanthropist the...