Originally Posted by
Tom M King
Edison chose 110v to power his working lights. Current pushed through lines was based off that, at 110, and 220 volts, until sometime in the 1930's, it was standardized, and upped in voltage to 120, and 240, to better allow for distances of lines. 110/220 is still an old carryover naming for the same thing. My Parents' generation always still called it 110, and 220, because that's what it was when they were growing up, and that has just carried over, now for several generations.