In my first apartment as an adult in NYC the power was 110V DC, powered from a generating plant around the corner! Had to get a noisy inverter to play my 78 rpm records. (For those who know New York, it was the lower east side, Ave. C and Stanton).
Edison's DC power plants were placed all over the city since it was not economical to transmit 110V DC at distances.
One frequency note: I have read that 25Hz is more efficient for large motors, and that parts of the European rail system uses it today. 60 Hz gets you beyond the noticeable flicker frequency for lighting.
Karl
