Impact of 220 volts growth in houses after WW2
In the usa many houses were only wired for 110 volts before WW2. It was not until about 1947 that newer houses being built had to have a minimum of 220 volt service and 60 amps. A 110 volt dryer is often only about 1300 watts; thus really not so powerfull. Many folks like me who grew up with 110 volt dryers still used clothes lines, a dryer had little drying power. In a 1960's city I lived in; there was still coal being burned and anything on the clothes line got black crap on it; thus a dryer was used more.