Or, if you don't feel like reading even that much, I'll jump to the punch line: Proctor and Gamble were trying to find cheaper ingredients to make soap. At the time, soap was made from animal fat. They came up with a mix of palm and coconut oils that worked well enough and Ivory soap was born.
But once they were on to vegetable oils, they figured they could get even cheaper. A German chemist developed a process to make cottonseed oil solid at room temperature. Proctor and Gamble bought the rights to the patent and started working on another new soap.
So far, so good. But then someone noticed that the stuff they were working on kind of looked like lard. And if you could replace animal fat with hydrogenated seed oil in soap, why not cook with it, too?
No, that could never work. Why would people switch from cooking with butter and lard to cooking with soap? Unless ... could they simply make up some claims that it's "healthy"? Boy, it's a good thing there were no laws governing food claims.