From Notices of the AMS
Mathematicians Confront Political Tests: The American Mathematical Society and the Red Scare, 1954
by Albert C. Lewis
Karen Hunger Parshall
Communicated by Laura Turner
"Five years after a world war has been won, men's hearts should anticipate a long peace, and men's minds should be free from the heavy weight that comes with war. But this is not such a period---for this is not a period of peace. This is a time of the Cold War. This is a time when all the world is split into two vast, increasingly hostile armed camps---a time of a great armaments race" [McC50]. So Senator Joseph McCarthy (R-Wis.) bellowed from the dais in Wheeling, West Virginia, in a Lincoln's birthday speech in February 1950. But, in McCarthy's view, it was even worse. "I have in my hand," he told his listeners, "57 cases of individuals who would appear to be either card-carrying members or certainly loyal to the Communist Party, but who nevertheless are still helping to shape our foreign policy" as employees of the US State Department.
Although the process of rooting out communists had already begun prior to McCarthy's speech, the Red-hunting mania that followed it in the 1950s was particularly intense.