As a man who has swung a sledge hammer for a living, and been to the Big Bend tunnel on the C&o canal, It's somewhere north west of Paw Pawpaw, and north but not far from the Potomac I have different takes on the song. First, the Luddite anti progress verses man of honor proud in his labor having dignity argument, guess a little of both sides. I ran survey crews for years, stopping every 25 or 50 feet to drive a hub and stake in the ground. I have also swung a hammer to break rock and concrete. I have used a 4,6,8,12,16 & 20 lb hammer. Never used a 9, go figure. One learns and gets to the point where a good steady pace becomes easy. Shaker held the star drill in place, a chisel with a head like an asterisk. He twisted it between swings to clear the broken rock, miss and if you don't smash the shaker's hand badly, a chip may fly off the drill steel, and it can cut you badly. Being out of practice on a supervisory project I had, I borrowed a contractor friends 20 lber. Fooling around I tried a roundhouse swing. Thought I might rip my pectorals from my body. Heart attack, stroke from over exertion, or just ripped his chest apart. He showed he could do it And I believe then he died.