Hershey founded the first mass market chocolate company in 1900. His chocolate bar was so popular that the company did not advertise it until 25 years after his death. The company’s sales grew rapidly from $622,000 in 1901 to $55 million in 1941. The Hershey factory was the world’s largest single entity engaged solely in the manufacture of chocolate cocoa, which spawned a private, self-contained community for employees.