LABOR FORCE The population of the United States has more than doubled in the more than sixty years since World War II, a fact that is important to any quantitative discussion. The 1940 census, taken in the year before the U.S. entry into the war, showed the nation to have a total population of just slightly over 130 million people. This was a historically small increase over the previous census, when the 1930 population was approximately 123 million: although they seldom acknowledged it, women clearly exercised some forms of birth control during the Great Depression of that decade. In contrast, the baby boom of the war and postwar years would create a jump to 151 million by 1950. That, in turn, would double during the second half of the century-at the same time, ironically, that individual family size declined.