According to a post on Fran Jurga’s Hoof Blog, the original Jack with his lantern was a blacksmith.

There once was an Irish blacksmith named Jack. He was a miserable man, and he spent his nights in the pub trying to make everyone around him miserable, too.

One night he made a deal for one more drink, but he had no money so it had to be paid for by the devil.

But to read the rest of the story you need to visit her post.

Happy Halloween!