First, who is "we"?
Are you old enough to have studied any US history yet?
You do know that the first European settlements in what is now the US were by Spanish Roman Catholics don't you?
You do know that the first English settlement in the US were strictly commercial and not affiliated or driven by any religion don't you?
You are aware of Henry's Church aren't you?
You do know that Christianity and the concept of a Religious State was the largest single problem faced in founding what became the US don't you?
You do know that absolutely none of that has anything to do with polygamy don't you?
Anyone so limited that they can only spell a word one way is severely handicapped!