"On January 1, 1802, President Thomas Jefferson wrote a letter to the Baptists of Danbury, Connecticut, who had requested clarification about the meaning of the First Amendment to the Constitution. Jefferson described the Establishment Clause of First Amendment by writing, “I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should make no law respecting an establishment of religion, or prohibit the free exercise thereof, thus building a wall of separation between church and state.”
A wall of separation between church and state. This is a very strong statement, very clear in meaning. First of all, it means that the government cannot make laws that favor one religion over any other, because it cannot make laws related to the establishment of a religion or the free expression of religious beliefs. Therefore, individuals can pray in school, but public schools cannot require people to pray. The government cannot endorse any particular religion — meaning there can be no copies of the Ten Commandments in front of schools, nor nativity scenes in government buildings, nor Buddha statues in front of government offices."