Abstract: During the Cold War, many scientists became advisors to the federal government, working with officials to develop policies that would serve America's Cold War agenda. Policymakers in Washington prized scientists as advisors because of their supposed objectivity. Many felt scientists should not step outside the boundaries of their technical expertise and attempt to offer input on how technology should be used. However, some scientists found the domestic and foreign policies of the U.S. government troubling, and they were uneasy about the role they, as the creators of the technology that fueled the Cold War, played in furthering those policies. After the end of World War II, many Manhattan Project scientists banded together with colleagues in other scientific disciplines to form the Federation of American Scientists (FAS). This 'scientists' movement'' had two goals: securing passage of legislation that would ensure civilian control and promote international cooperation on atomic energy, and the education of the American public about the dangers of the nuclear age. In their efforts to make the public aware of the need to control atomic power, scientists of the FAS found themselves in an uncomfortable position. Although they insisted their mission was to simply provide the 'facts' to a public in need of guidance, they realized that the process of educating the public might necessitate sacrificing their public image of objectivity and advocating a particular position on the issue of atomic energy control. This dissertation explores the dilemma over objectivity that the FAS encountered during the early years of the Cold War. I argue that although this problem nearly derailed the scientists' movement, the scientists of the FAS eventually contested the notion that scientists could not take a political position, and in so doing staked a claim as representatives for a science that would serve the public interest. They advocated for transparency in the creation of public policy, worked to limit military control over science, and argued for the preservation of the health and safety of all human beings. The FAS set a precedent for future scientific groups that would later take up the cause of promoting public-interest science.