No suitable person is known to be the original for this. Probably intended as a substitute for hell or, more fully, for "damned hell".
One speculative possibility for the origin of this expression is that it derives from the Swedish samhället (“community”). An early Swedish immigrant to the United States might have said, "Nu ver in de samhället has Johnny gone to?!"; samhället (“community”) became anglicized, repeated, and immortalized.
- (slang) An intensifier.
- What the Sam Hill do you think you're doing?
- Who the Sam Hill does he think he is?
- Where in Sam Hill is that dog off to?
- 1960, Harper Lee, To Kill a Mockingbird, ch. 3,
- Walter poured syrup on his vegetables and meat with a generous hand. He probably would have poured it into his milk glass had I not asked what the sam hill he was doing.