For decades, big business and environmentalists have battled over access to America's rivers. Now that dams are being torn down in record numbers, we went back to the one that started it all for some clues about what happens next.Driving on the eastern bank of the Kennebec River, past several "No Trespassing" signs and across a set of railroad tracks, I turn onto a narrow access road pocked with potholes. It cuts in front of the worn, empty buildings of an abandoned tissue factory, part of another era in Maine's capital of Augusta. I spot a guy in a hard hat and pull over. I'm looking for the Edwards Dam, I tell him. He straightens up, takes off his hard hat. "You know, come to think of it," he says, "I think they tore that down."