In short, it's "everything but the oink." All of the scraps from pig (and I do mean ALL of the scraps) are finely ground, mixed with cornmeal and spices, formed into a loaf, sliced, and then pan fried before serving. Now that's some good eats!
Originally, scrapple offered the colonial Pennsylvania-Dutch a way to conserve expensive meat that would otherwise go unused. It's still enjoyed by the descendents of these hardy colonists, including the Amish and Mennonites.
From the Pennsylvania-Dutch, this dish spread into parts of Appalachia in the form of liver-mush (I'm thinking this would be a good follow up segment).
Eat good food. Drink good beer. And above all, stay classy!