Oh, and by the way, even if it were made applicable to the states, the First Amendment would NOT have made the Ten Commandments unconstitutional.
We did much worse in the early part of our country that was upheld by the courts.
1) paying for Bibles
2) paying missionaries and sending them with govt. blessing to the Indians....and using public money to pay for churches on Indian land
3) having church in the capitol building and original SCOTUS building....with govt. officials often in attendance, a clear endorsement of the services.
4) Strongly endorsed and sometimes required church attendance by the U.S. military, even during the Civil War pushed by Lincoln himself.
I was required to attend church service in bootcamp as recently as 1967