Where Does a Wall Begin?

In a client’s mind, when she thinks to herself one day, “There should be rocks here”?

When a trench is dug and filled with crushed stone to give the imagined wall a solid foundation?

With the setting of the first stone?

Or when the stone is selected at an abandoned quarry in New Hampshire, loaded onto a semi, and trucked to Maine?

Or did it begin a hundred and fifty years or so ago, when quarry workers broke the bond between stone and ledge, drilled and hammered and laid the stone up in massive piles, leaving it to sit and weather until now, for people and a purpose they never imagined?