The interpretation of the Establishment Clause has in large part been in cases involving education, notably state aid to private religious schools and prayer in public schools. In Everson v. Board of Education, for example, the issue was whether a New Jersey local school board could reimburse parents for expenses incurred in transporting their children to and from Catholic schools. The reimbursement was part of a general program under which all parents of children in public schools and nonprofit private schools, regardless of religion, were entitled to reimbursement for transportation costs. Justice Hugo Black, writing for a sharply divided Court, justified the reimbursements on the child benefit theory, i.e., that the school board was merely furthering the state’s legitimate interest in getting children “regardless of their religion, safely and expeditiously to and from accredited schools.” The Court, after narrating the history of the First Amendment in Virginia, interpreted the Establishment Clause, viz:
The ‘establishment of religion’ clause of the First Amendment means at least this: Neither a state nor the Federal Government can set up a church. Neither can pass laws which aid one religion, aid all religions, or prefer one religion over another. Neither can force nor influence a person to go to or remain away from church against his will or force him to profess a belief or disbelief in any religion. No person can be punished for entertaining or professing religious beliefs or disbeliefs, for church attendance or non-attendance. No tax in any amount, large or small, can be levied to support any religious activities or institutions, whatever they may be called, or whatever form they may adopt to teach or practice religion. Neither a state nor the Federal Government can, openly or secretly participate in the affairs of any religious organizations or groups and vice versa. In the words of Jefferson, the clause against establishment of religion by law was intended to erect “a wall of separation between Church and State.”
The Court then ended the opinion, viz:
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. New Jersey has not breached it here.