It's the birthday of a man considered to be one of the most popular best-selling children's book writers in American history and a man who revolutionized the way children learned to read, Theodor Geisel, better known as Dr. Seuss. He was born in Springfield, Massachusetts, on this day in 1904. He's the author of more than 60 children's books, including Horton Hears a Who! (1954), One Fish, Two Fish, Red Fish, Blue Fish(1960), Green Eggs and Ham (1960), Hop on Pop (1963), Oh, the Thinks You…