H.W. Hill & Co. of Decatur Illinois, the sole manufacturer of Hill’s hog ringers, produced this map called “Nicknames of the States.” It is from 1884. The Library of Congress has it for free download in a variety of resolutions. I found my new desktop background!
There is a pig for every state in the union, and each pig sports a triangular nose ring.
The nickname for a Missouri pig is “Puke.”
(Via This Isn’t Happiness NSFW)