Corn Flakes
Dr. John Harvey Kellogg and his brother, Will Keith Kellogg, operated a sanitorium in Battle Creek, Michigan back in the late 1890s. While looking for foods to feed their patients that were part of their strictly vegetarian diet, the duo accidentally left wheat berry cooking in the kitchen, causing the kernels to flake.
They continued to experiment with their newly discovered breakfast food, eventually experimenting with corn and creating the Corn Flakes we know and love today.