Edison distributed ±110V DC against neutral, three wires, your AC system was designed to use those exact wires, then you expanded that compromise to the whole continent.
Europe in the beginning also had those small insular installations with odd systems but once it came to actually hooking up whole countries everyone opted for three-phase because it’s the most sensible option. Whether or not the distribution network itself uses three conductors (just the phases) or four (plus neutral, or combined earth+neutral) differs quite wildly. Train electricity is still a clusterfuck.
Edison distributed ±110V DC against neutral, three wires, your AC system was designed to use those exact wires, then you expanded that compromise to the whole continent.
Europe in the beginning also had those small insular installations with odd systems but once it came to actually hooking up whole countries everyone opted for three-phase because it’s the most sensible option. Whether or not the distribution network itself uses three conductors (just the phases) or four (plus neutral, or combined earth+neutral) differs quite wildly. Train electricity is still a clusterfuck.