"Cracker Jack box"
Cracker Jack is a longtime U.S. brand of snack consisting of caramel corn and peanuts, well known for featuring a cheap “Toy Surprise Inside.” First marketed at the Chicago World’s Fair in 1893, three years later its makers devised a way to keep the caramel corn from getting stuck together in huge chunks. It was immortalized in the baseball song, “Take Me Out to the Ball Game” in 1908 (“… buy me some peanuts and Cracker Jack….”). The prizes were introduced in 1912 (the “white celluloid set of teeth” mentioned in chapter 47 is evidently a prize characteristic of the 1920s or 1930s when Bradbury was a boy), though in later years the plastic toys and trinkets were replaced with tiny paper booklets and sheets containing riddles and jokes.