The invention of the popular putty like toy was actually a accident in the 1930s. Noah McVicker of Cincinnati, Ohio created the product from water, flour, salt, boric acid, and mineral oil. His families soap company marketed the mixture as wallpaper cleaner. Eventually teachers in the area realized the wallpaper cleaner was harmless and could be used for kids craft projects at school.
Post WWII
It wasn't until after Wolrd War 2 that Noahs nephew Joseph McVicker realized the product was being used in schools for crafts. He decided to appropriately name the product "Play-Doh", and market it to schools, teachers and department stores. By 1956 Play-Doh was a success and sales hit 3 million.
Modern Day
Play-Doh was then bought by Hasbro and it still sold through its Playskool toy line. In 2003 Toy Industry Association added Play-Doh to its "Century of Toys List" which list the 100 most memorable and creative toys of the last 100 years