National Play-Doh Day celebrates a great childhood play toy.
Invented in the mid 1950s, it has entertained millions of children,
and allowed them to express their creativity. Play-Doh was created in 1955
by Joseph McVicker of Kutol Chemicals in Cincinnati, Ohio.

It hit the market in 1956, and has been a  popular play toy ever since.
According to Hasbro Toys, the current makers of Play-Doh,
The story of PLAY-DOH modeling compound begins in 1956 when scientists at Rainbow Crafts, a Cincinnati soap and cleaning compound company,
stumbled upon a new use for the unique dough-like cleaning product.
The company realized this product’s potential as a child’s modeling compound;
and thus, the original, reusable PLAY-DOH compound was born.
source: http://www.holidayinsights.com

The Benefits of Play.
While play is crucial for a child’s development,
it is also beneficial for people of all ages.
Engaging in play can add joy to life, relieve stress, supercharge learning,
and connect you to others and the world around you.
Play can also make work more productive and just perhaps, a little more fun.
source: https://www.helpguide.org