Once an Ancient Toy, Yo-Yoing is Now a World Sport Enjoyed by All Ages Middlefield, OH – (June 5, 2020) – Duncan® Toys, one of the oldest and best-known toymakers, celebrates National Yo-Yo Day on June 6th, 2020. From Ancient Greece in 440 B.C. to Nasa Space Missions, the yo-yo has traveled through time and transformed from a leisure toy and science instrument to a global sport. First popularized in the U.S. by Donald Duncan during the Great Depression, the story of the yo-yo is unique: one...