"The first Commandment says: "I am the Lord thy God. Thou shalt not have strange gods before me."

A statement like this has no business on public property in a nation that professes to protect religious freedom."

Why not?
You could gain some enlightenment- if you understood it.

"Judge Moore claims the Commandments are the foundation of our federal law."

Which is a true statement, that anyone who has a clue would understand.

"In effect, he is saying that I, an American citizen, must pray to a god of his choice and not my own."

How is he compelling you to do anything. And how could you possible know what God he is "making" you to pray to?
You know if all "we" had to do was write things down and people would follow them, our world would be quite simple. Simple and quite boring.