One thing I think we need to put into context of the time on this threat was back during those days, people thought of themselves as being from the state they were born in and not America. They called themselves Georgians, Virginians, New Yorkers, not Americans. Which ever state you were from held your loyalty much more than to the United States as a whole.
It wasn’t until the Spanish American War that we actually started to think of ourselves as Americans instead as Georgians, Alabamans, Delawareans, and Marylanders etc. WWI pushed that thinking along and finally during WWII we finally looked at ourselves as Americans and not being just from the state we were from.