Many today think that our nation was founded on the premise that the federal government may have no association with religion. Actually, that is a fairly recent invention of the courts and does not reflect the manner in which our founders behaved.
Consider that during World War II the United States Government Printing Office printed a book for the use of our troops that they thought would be useful. It was the "Song and Service Book for Ship and Field, Army and Navy." According to the Smithsonian National Museum of American History, "The Song and Service Book for Ship and Field, Army and Navy, edited by Ivan Loveridge Bennett, features prayers, hymns and patriotic songs used in various military ceremonies and religious services."
Read more on the Smithsonian website.