Looks almost like it was made out of a rail road spike, it doesn't look like a wood splitter but more like a chisel for breaking bricks or cleaning up limestone blocks for old houses or buildings. Pretty neat either way.
Well, whatever it is it was beat on pretty good. The end where the sledge would hit is smashed down over the edges. My guess is a wood splitting wedge. Still have nightmares of splitting elm with those things.