Dear x-ray machine: pretend you don't know me so well

An enlightening walk in the parking lot today brought to my attention the fact that Missouri's state nickname is "the Show Me State." The way I see it, there are only two connotations with the phrase "show me." 1) Skepticism. Missouri is proud to host citizens who disbelieve anything they don't see for themselves; they demand ocular proof to the point that they put it on the license plates. 2) Some sort of innuendo.

In case anyone is wondering, Illinois' nickname is the Prairie State. I'm wondering what kind of thumb war/corn growing deathmatch went down to wrestle that title away from Indiana (Hoosier State) or Iowa (Hawkeye State. After a college? Really?).