score:8
Citing a U.S. Census Bureau publication, "Historical Statistics of the United States, Colonial Times to 1970," this website of the Federal Reserve Bank of Richmond shows a graph indicating that in 1940, 85% of all US residences had access to electricity.
Statista, crediting their own research department, provides a bar graph that indicates that in 1940 36.9% of all US housing units had a telephone. This site shows a graph based on US government sources confirming that number. The site owner requests that it be cited as: Rodrigue, J-P et al. (2020) The Geography of Transport Systems, Hofstra University, Department of Global Studies & Geography, https://transportgeography.org.