one of the patients at the health center was a man named Charles post. as he walked around the health center, he watched how the cereal was made. when he returned home, he started his own cereal company. By 1900, the post Cereal Company was making 3 million in sales. About time, more than twenty other breakfast companies started in battle creek---all making cereal. the kellogg brothers were angry that people were using their ideas and getting rich.