Freedom of Expression and Conscience
The First Amendment guaranteed Americans freedom of expression and conscience, and author James Madison considered it utterly crucial to preserving citizens' liberty. The amendment protects citizens' right to speak or publish their opinions and to gather to protest against their government.
The amendment also protects citizens' freedom of religion and freedom from religion. The long history of religious warfare and intolerance in Europe (as Catholics and Protestants battled against one another in the wake of the Protestant Reformation) caused many American leaders to distrust and even fear any partnership between government and religion. The First Amendment's establishment clause ("Congress shall make no law respecting an establishment of religion") specifically prohibits government from favoring any particular religious faith, and, in the opinion of many Americans, forbids government from favoring religion generally. The free exercise clause ("nor prohibiting the free exercise thereof") prohibits government from interfering in the faith of an individual citizen or group of believers.