I live in Indiana, midwestern US. We are called Hoosiers. Don't ask me why!
Here are a couple of "stories" about how the term Hoosier could have come about:
One idea suggests the term was a greeting. When approaching a man's home in early frontier days, one shouted from afar, "Hello, the cabin!" to avoid being shot. The inhabitants would then shout back "Who'sh 'ere?" (who's here). Soon the words became slurred together, and the country folk came to be called Hoosiers.
Many Indiana social studies teachers tell a story of two French men that had migrated to Indiana in the 1800s. They were in an old-time tavern somewhere in the foothills of southern Indiana. A fight broke out between the two, which led to one of the men getting an ear cut off. The story says that a third French man walked in to see an ear on the dirt floor of the tavern and shouted "Who'sh ear?"