I stand corrected for my error of stating 1964 when it should have been 1947; the rippling effects of one Supreme Court decision:
Everson v. Board of Education (1947) in which the Supreme Court declared, 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.
McCollum v. Board of Education (1948) in which the court declared that religious instruction in public schools is unconstitutional.
Tudor v. Board of Education (1954) The Supreme Court let stand the lower court ruling, Tudor v. Board of Education against the distribution of Bibles by outside groups like the Gideons.
In 1960: Madalyn Murray O'Hair sued the Baltimore MD school system on behalf of her son William J Murray, because he was being forced to participate in prayer in schools.
Torasco v. Watkins (1961), by unanimous decision, ruled that any religious test for state office holders is unconstitutional.
Engel v. Vitale (1962) in which the court declared school prayer unconstitutional (disallowed a government-composed, nondenominational "Regents" prayer recited by students).
Abington Township School District v. Schempp (1963) in which the court declared Bible reading over the school intercom unconstitutional.
Murray v. Curlett (1963) in which the court held that it is unconstitutional to force a child to participate in prayer.
Stone v. Graham (1980) in which the court outlawed the posting of the Ten Commandments in a school even if it is done for a secular purpose.
Wallace v. Jaffree (1985), the high court voted 6-3 to strike down an Alabama law requiring public schools to set aside a moment of silence for meditation or prayer.
Lee v. Weisman (1992), the Court ruled that public schools may not sponsor invocations at graduation ceremonies.
There are those whose goal it is to strip America of God. I'm sorry you focused on the year and attributed this to me "playing."