In most electrical systems one of those ground wires is also connected to a neutral wire that leads back to the generator. But there do exist "Single Wire Earth Return" systems where the neutral return wire is omitted and everything still works. https://en.m.wikipedia.org/wiki/Single-wire_earth_return
Am I wrong?
Neutral can also be connected to a neutral line on the grid. But you pretty much always want to connect it to the local ground through a literal metal post.
Neutral and ground are bonded together in the service entrance. The neutral is a center tap off the utility transformer and the ground is usually a ground rod.
In older houses the service entrance is typically the main panelboard. In a house built after 2020, the service entrance will be a disconnect switch after the meter socket.
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.