If your most recent memories of jacks involve treading carefully to avoid stepping on their evil points, you might be surprised to learn the long and storied history of this beloved toy. Historians suggest that children have played some version of this game since the Cro-Magnon period, when kids scooped up rudimentary jacks to improve hand-eye coordination for hunting [source: Strong National Museum of Play]. Long before the days of modern metal jacks and bouncy rubber balls, kids fashioned jacks from the knucklebones of sheep or simply used beans, rocks or pits from fruit. Balls were made from wood, or kids simply tossed a rock in the air and tried to scoop up as many jacks as possible before the stone hit the ground. The song "This Old Man" was developed by young jacks players as a means of counting their progress through the game.