This book examines the lives and contributions of American women physicists who were active in the years following World War II, during the middle decades of the 20th century. It covers the strategies they used to survive and thrive in a time where their gender was against them. The percentage of woman taking PhDs in physics has risen from 6% in 1983 to 20% in 2012 (an all-time high for women). By understanding the history of women in physics, these gains can continue. It discusses two major classes of women physicists; those who worked on military projects, and those who worked in industrial laboratories and at universities largely in the late 1940s and 1950s. While it includes minimal discussion of physics and physicists in the 1960s and later, this book focuses on the challenges and successes of women physicists in the years immediately following World War II and before the eras of affirmative actions and the use of the personal computer.