What are subtopics for chocolate?

How about the history of chocolate, how the Aztecs made a thick hy liquor out of it, and also it's many different uses...in cakes, frostings, milkshakes, bars, and how it used to be included in the rations given to American soldiers in the 1940's. Mention that there is also two kinds, sweetened and unsweetened, and if you were raised a southerner as I was you could also mention the sunday morning treat of biscuits with chocolate gravy--so delicious !!!