The modern gendering of toys, specifically marketing different toys to boys and girls, originated in the 1940s to increase sales.

“But in the 1940s, they were like, "Hey, we could probably sell a lot more stuff if we really market one thing to girls and one thing to boys." And then all of a sudden, we're buying twice as much stuff. Isn't that nuts? That's That's apparently where gendered toys came from.”