Due to its Constitution, and particularly to that Constitution’s First Amendment, the relationship between religion and politics in the United States is rather unusual. This is especially the case concerning the manner with which religious terminology is defined via the discourse adopted by the United States Supreme Court, and the larger American judicial system. Focusing on the religious term of Atheism, this book presents both the discourse itself, in the form of case decisions, as well as an analysis of that discourse. The work thus provides an essential introduction and discussion of both Atheism as a concept and the influence that judicial decisions have on the way we perceive the meaning of religious terminology in a national context. As a singular source on the Supreme, Circuit, and District Court cases concerning Atheism and its judicial definition, the book offers convenient access to this discourse for researchers and students. The discursive analysis further provides an original theoretical insight into how the term ‘Atheism’ has been judicially defined. As such, it will be a valuable resource for scholars of religion and law, as well as those interested in the definition and study of Atheism.