jigsaw puzzle:

Beginning in the 1930, The Judy Company of Minneapolis produced wood, or Masonite, frame puzzles for toddlers. Discovering there was a market for such educational toys, the firm continued to expand through most of the 20th century, specializing in toys such as the Judy Clock and various other toys made to benefit the child that played with them. The firm was ahead of its time in other ways as well, hiring disabled individuals, encouraging employees to unionize, and making puzzles with positive images of African American people at work and at play.