First Amendment to the United States 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.
Incorporation to the states
Speech and press clauses: For present purposes we may and do assume that freedom of speech and of the press—which are protected by the First Amendment from abridgment by Congress—are among the fundamental personal rights and ‘liberties' protected by the due process clause of the Fourteenth Amendment from impairment by the States.
Establishment clause: The meaning and scope of the First Amendment, preventing establishment of religion or prohibiting the free exercise thereof, in the light of its history and the evils it was designed forever to suppress, have been several times elaborated by the decisions of this Court prior to the application of the First Amendment to the states by the Fourteenth.