Praying

Voluntary school praying was constitutional from 1789 until 1962. Then, why is it illegal now? At least, that's what history points out, doesn't it? Similarly, if the Ten Commandments are also outlawed, why did Framers of our Constitution and earlier courts allow them? Why was nothing present to prohibit posting them until 1980? Something "fishy" here, so to speak. Courts reached different decisions that are opposite of more recent conclusions when ruling on the same issues. Go figure. To illustrate the point, in 1844, the U.S. Supreme Court concluded that the instruction of the Bible was to be included in government-run schools. That's a reversal from today. Isn't it strange that America used to include prayer and the teachings of the Bible as part of the public marketplace and schools? What gives? What changed? Who is changing all this today?