What is first packaged cereal?

The first packaged cereal is generally considered to be Granula, created by James Caleb Jackson in 1863.

While not exactly the modern cereal we know today, Granula was a coarse, graham flour-based product that was meant to be soaked overnight and eaten for breakfast.

It was sold in bulk, not individual boxes, and wasn't particularly palatable, leading to its eventual decline in popularity.

However, it paved the way for the development of modern cereal, and Jackson is often credited with starting the cereal industry.