Yup. Short range runs could be two wires, it was more cost effective given the poor performance of the earth return system. Much longer runs were a single condu

Yup. Short range runs could be two wires, it was more cost effective given the poor performance of the earth return system. Much longer runs were a single conductor on the pole. At either end you'd have a gigantic metal plate sunk deep into the ground to act as your return path. It had to be deep enough to stay wet, or the operator would have to dump water (or other fluid) on it. There were also repeaters in the transcontinental run, the signal was just way too weak. These were initially electromechanical devices that dip a needle into a pool of mercury. Things were wild before we really invented electronics.