U.S. Census BureauThis 1940 map identifies major cities,
mountains and rivers in California. The National Archives
released for the first time yesterday individual records from
the 1940 Census – unleashing an online treasure trove of 3.8
million pages eagerly awaited by genealogists and researchers.
The country has changed substantially in 72 years: Its
population has ballooned to nearly 309 million from 132 million.
Alaska and Hawaii were not yet states. California's entire
population, 6.9 million, was less than Los Angeles County's
today. California's population in 2010, more than 37 million,
was the nation's largest. In 1940, it was the nation's fifth-
largest, trailing New York, Pennsylvania, Illinois and Ohio. But
California led the nation in other ways, including educational
attainment. While just 24.5 percent of Americans had earned at
least a high school diploma in 1940, more than 37 percent of
Californians had – the highest rate in the country. It also had
the highest rate of college graduates among s