The short story by Mark Twain. It was his first great success as a writer and brought him national attention.
In it, the narrator retells a story he heard from a bartender, Simon Wheeler, at the Angels Hotel in Angels Camp, California, about the gambler Jim Smiley. The narrator describes him: "If he even seen a straddle bug start to go anywheres, he would bet you how long it would take him to get to wherever he going to, and if you took him up, he would foller that straddle bug to Mexico but what he would find out where he was bound for and how long he was on the road."