On the recordMay 12, 1998
I might mention, because I have read comments from different city officials and the city of Republic, and they make the point that that is meant to be an emblem of religion, the principles of religion generally as opposed to saying it has to be any one particular faith. Indeed, I asked the Congressional Research Service to look at this for me. They gave me information today that, actually, the symbol of a fish has been used for thousands of years around the world, even before Christianity has been used for a thousand of years, even before the life of Christ as a religious symbol. They indicated it had been used in China, in India, in Egypt, in Greece, in Rome in Scandinavia, in the Mideast, even before Jesus Christ was born.
Source
govinfo.gov
