According to the Encyclopedia of American Economic History, "Rosie the Riveter" inspired a social movement that increased the number of working American women from 12 million to 20 million by 1944, a 57% increase from 1940.[citation needed] By 1944 only 1.7 million unmarried men between the ages of 20 and 34 worked in the defense industry, while 4.1 million unmarried women between those ages did so.[23] Although the image of "Rosie the Riveter" reflected the industrial work of welders and riveters during World War II, the majority of working women filled non-factory positions in every sector of the economy. What unified the experiences of these women was that they proved to themselves (and the country) that they could do a "man's job" and could do it well.[24] In 1942, just between the months of January and July, the estimates of the proportion of jobs that would be "acceptable" for women was raised by employers from 29 to 85%.[citation needed] African American women were some of those most affected by the need for women workers. It has been said that it was the process of whites working along blacks during the time that encouraged a breaking down of social barriers and a healthy recognition of diversity.[24] African-Americans were able to lay the groundwork for the postwar civil rights revolution by equating segregation with Nazi white supremacist ideology.[24]