The First Amendment (Amendment I) to the United States Constitution prohibits the making of any law respecting an establishment of religion, impeding the free exercise of religion, abridging the freedom of speech, infringing on the freedom of the press, interfering with the right to peaceably assemble or prohibiting the petitioning for a governmental redress of grievances. It was adopted on December 15, 1791, as one of the ten amendments that constitute the Bill of Rights.
Full article here: http://en.wikipedia.org/wiki/First_Amendment_to_the_United_States_Constitution
