WE have have many many forts along most port cities that served much earlier than the civil war. In reality many forts were built, rebuilt, and added to over the decades of time. The owners and enemies varied over the years. Even though we started out over here 'officially' in 1492, a native population of nomadic and non nomadic native Indians were already well settled. It is very interesting what we chose to bring over from the mother land and what we did not. Castles represented centralized power, and form its very beginning, America was about every man making his way himself, taking care of himself, paving his path into the wild. Centralized power is what most colonists were running form. Just a thought. I did a 9 day driving tour of Ireland, and it was simply spectacular. Also went to london a couple of times for F1 races. Your entire country, is breathtakingly beautiful!