110 volts was adopted in the USA due to Edison pressure. Why?
To run an electric item, one needs a certain power which is Volts x Current. So when you use 220 volts, you spend 1/2 current. The loss along a power line are proportional to the current and the cross section (and length) of a wire. Get it? This is why the rest of the world is using 220-240 volts. Japan, Taiwan and USA are the only one to use 110 volts. This is why as well the electricity is transported from power plant at very high voltage (110kv ) and brought to neighbourhood step-down transformers.
So in the USA, they face 2 issues: increasing diameter of cable, which makes network more costly or having more losses. Practically they play on both side.
OK, let's come back to our story's beginning : why did bloody Edison pushed you in such system? Usually people says: because 110 volts is safer. Wrong answer because, as we've seen, the 110 volts carries twice the current. And for damages on human body, it's power that matters. No, Edison was worried to sell reliable bulb. At this time, bulb were using carbon filaments. With 110 volts the filaments can be of an acceptable diameter. But to give a correct light, the filaments will have to be to thin, which was difficult to produce industrially at that time. Remember we have seen that loss on a wire i.e. thermic losses are proportional to cross section. So USA is using 110 volts current just because of bulbs of Mr. Edison. ..