Civil War Cannon @ Sunset

One sunset, walking around Fort Morgan, I captured this of one of the cannons near the Postern.   It's a pretty major gun and the resonating thought that stuck with me was:  "This gun was used against fellow countrymen."

A chilling thought.

I wonder what a civil war would look like in America today.  Would the borders be geographic? Probably not.   
Social, political, racial or religious? Maybe.   Borders based on economic classification.  More likely.