One of your fellow noders is related to the "under-privileged children" which Milton Hersey's school raised, mentioned in chacha's writeup. My family is from east-central Pennsylvania. My mother's parents died when she was very young. While my mother and sister were adopted by an aunt, they could not afford to take in my mother's five brothers. The boys were raised by the Hershey School for Boys (as the orphanage was known in the 1930's).
My own memory of Hershey comes, however, from school field trips. In the late 1960's the tour of the factory was not "simulated" in theme-park style, as it is today. Until 1973, you could tour the actual factory: behind glass, but right in the heart of the shiny beast. At one point in the process of making chocolate, the chocolate "liquor" (liquified "nibs" of cacao beans after the shells are removed) is heated and rolled with giant granite rollers for up to 72 hours, to remove the gritty texture of the cocoa and mix it with cocoa butter. This process is called conching. The conching machines at Hershey were enormous: the size of swimming pools. Whenever I melt baker's chocolate for brownies I am reminded of those rollers pushing great waves of molten chocolate around, the heat radiating through the glass, and the overwhelming delicious smell.
We also saw great assembly lines pouring and wrapping and packaging the individual Hershey Kisses and candy bars, and got some free chocolate at the end of the tour, but the conching machines are the part I remember well, 30 years later.