I know this is a complicated political and legal issue, and I have no way of knowing if we will ever return to the patterns of the past. Unfortunately, the general trend in our society is certainly away from God and against any public expressions of faith.
I hope you will keep several things in mind, however. First, no one can banish God from our hearts. If we truly know Christ, we know we can turn to Him in silent prayer no matter where we are. Do you remember Nehemiah in the Old Testament? He was an official in the palace of the pagan king of Persia, but when God gave him an opportunity to speak to the king on behalf of the Jewish people, Nehemiah prayed silently and then spoke: "I prayed to the God of heaven, and I answered the king" (Nehemiah 2:4-5).
Second, never forget the important place of our families in helping our children come to believe in God and rely on Him. No school or other institution can take the place of a family where God is honored and served.
Finally, we need to remember to pray for our country. The issue you mention here is only one sign of our nation's increasing drift from God. Pray for our nation and its leaders every day. The Bible says, "Blessed is the nation whose God is the Lord" (Psalm 33:12).