First Amendment to the U.S. Constitution

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the People peaceably to assemble, and to petition the Government for a redress of grievances.

The First Amendment to the U.S. Constitution, which was adopted in 1791, protects the core liberties of a free society:  freedom of conscience, freedom of expression, the right to criticize the government, and the right to participate in the political process.  It is one of the most eloquent, and most important, provisions of the Constitution. 

Unfortunately, the First Amendment is neither self-defining nor self-enforcing.  What is an “establishment of religion”?  What constitutes the “free exercise” of religion?  What is “freedom of speech”?  What is “freedom of the press”?  What does the right “peaceably to assemble” mean?  What does the right to “petition the Government for a redress of grievances” mean?  While these words and phrases sound beautiful, they are subject to a multitude of meanings and interpretations, which have challenged and perplexed courts for more than a century.  Indeed, the First Amendment repeatedly has been the subject of court cases, often very controversial, aimed at defining and clarifying what these terms mean in practice and what kinds of conduct they do and do not protect from government control and oppression.