Mister Rogers' Neighborhood (1968)

Season 14: Episode 4

Mister Rogers brings with him a box full of colored blocks. He takes them to the kitchen were he uses them to build a bridge. He also has with him a handful of marbles which he shows before watching films on how people use and make marbles. In the Neighborhood of Make-Believe, Lady Elaine and Lady Aberlin take Bob Dog with them to Southwood to find out what exactly is going on. Upon their arrival, they learn that the parts Corney made have been used to build a bridge, not for building bombs.