From the Bill of Rights
Ratified effective December 15, 1791

Amendment I
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.


“…Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof…”

FYI—
For an historical reference point for how the 1960’s Supreme Court justified the reinterpretation of the “establishment clause,” read about the origin in American history of the “Wall of Separation” as it was mentioned by Thomas Jefferson in a letter he wrote to the Danbury Baptists of New England.
Go to http://www.wallbuilders.com/libissuesarticles.asp?id=65 and read the actual letters.