What was the first breakfast cereal?

The first breakfast cereal was Granula, invented by James Caleb Jackson in 1863.

It wasn't the cereal we know today, though! It was a hard, graham-like biscuit that needed to be soaked overnight before it could be eaten. It was considered a health food and was marketed as a way to improve digestion.

While Granula wasn't a huge commercial success, it paved the way for the development of other breakfast cereals, and eventually, the modern cereals we enjoy today.