The acute manpower shortages brought on by the war seemed to hold out new hope for women professionals, especially in the sciences. In one of the first propaganda films produced by the United States Office of War Information in 1942, Katharine Hepburn narrated a script written by Eleanor Roosevelt, urging women to apply for jobs in government industrial science projects. But the public posture of welcoming women into the scientific professions masked a deep-seated opposition to change. Most scientific jobs for women were entry-level, and promotions to higher positions reserved for men. This text shows how women scientists nonetheless made significant contributions effort, ranging from engineering and nutrition (where both Margaret Mead and Rachel Carson worked well outside their areas of expertise) to metallurgy and the Manhattan Project. But it tells also of the post-war period, when women scientists were told to accept demotion cheerfully and American colleges began concerted efforts to get the old girls out and replace them with all-male - and therefore higher-paid and more prestigious - faculty. The author concludes that the period from 1940 to 1972 was a time when American women were encouraged to pursue an education in science in order to participate in the great professional opportunities that science promised. Yet the patriarchal structure and values of universities, government, and industry confronted women with obstacles that continued to frustrate and subordinate them. Nevertheless, women scientists made genuine contributions to their fields, grew in professional stature, and laid the foundation for the period after 1972 which saw real breakthroughs on the status of women in America.