<P> The incorporation of the First Amendment establishment clause in the landmark case of Everson v. Board of Education has affected the subsequent interpretation of the separation of church and state in regard to the state governments . Although upholding the state law in that case, which provided for public busing to private religious schools, the Supreme Court held that the First Amendment establishment clause was fully applicable to the state governments . A more recent case involving the application of this principle against the states was Board of Education of Kiryas Joel Village School District v. Grumet (1994). </P> <P> Jefferson's concept of "separation of church and state" first became a part of Establishment Clause jurisprudence in Reynolds v. U.S., 98 U.S. 145 (1878). In that case, the court examined the history of religious liberty in the US, determining that while the constitution guarantees religious freedom, "The word' religion' is not defined in the Constitution . We must go elsewhere, therefore, to ascertain its meaning, and nowhere more appropriately, we think, than to the history of the times in the midst of which the provision was adopted ." The court found that the leaders in advocating and formulating the constitutional guarantee of religious liberty were James Madison and Thomas Jefferson . Quoting the "separation" paragraph from Jefferson's letter to the Danbury Baptists, the court concluded that, "coming as this does from an acknowledged leader of the advocates of the measure, it may be accepted almost as an authoritative declaration of the scope and effect of the amendment thus secured ." </P> <P> The centrality of the "separation" concept to the Religion Clauses of the Constitution was made explicit in Everson v. Board of Education, 330 U.S. 1 (1947), a case dealing with a New Jersey law that allowed government funds to pay for transportation of students to both public and Catholic schools . This was the first case in which the court applied the Establishment Clause to the laws of a state, having interpreted the due process clause of the Fourteenth Amendment as applying the Bill of Rights to the states as well as the federal legislature . Citing Jefferson, the court concluded that "The First Amendment has erected a wall between church and state . That wall must be kept high and impregnable . We could not approve the slightest breach ." </P> <P> While the decision (with four dissents) ultimately upheld the state law allowing the funding of transportation of students to religious schools, the majority opinion (by Justice Hugo Black) and the dissenting opinions (by Justice Wiley Blount Rutledge and Justice Robert H. Jackson) each explicitly stated that the Constitution has erected a "wall between church and state" or a "separation of Church from State": their disagreement was limited to whether this case of state funding of transportation to religious schools breached that wall . Rutledge, on behalf of the four dissenting justices, took the position that the majority had indeed permitted a violation of the wall of separation in this case: "Neither so high nor so impregnable today as yesterday is the wall raised between church and state by Virginia's great statute of religious freedom and the First Amendment, now made applicable to all the states by the Fourteenth ." Writing separately, Justice Jackson argued that "(T) here are no good grounds upon which to support the present legislation . In fact, the undertones of the opinion, advocating complete and uncompromising separation of Church from State, seem utterly discordant with its conclusion yielding support to their commingling in educational matters ." </P>

Does the us constitution guarantee separation of church and state