Visiting locations?
1) I have sailed the north and south Atlantic oceans. A lot.
2) I have visited Portsmouth, and London, England.
3) I spent a great deal of time at Mystic Seaport, Mystic, CT, and know my way around a 19th century ship.
4) A close personal friend was assigned to Thule Air Force base.
5) I was assigned to, and traveled extensively in, Central America.
6) I spent a year at the Brooklyn Navy Yards.
7) My induction physical was at the old War Department building on Whitehall Street in NYC. (Yeah, I know it wasn't there during the Civil War. But there weren't magically-powered warships during the Civil War either.) I needed something that overlooked New York Harbor, and that was handy.
8) I have a pretty good memory, I use the library a lot, and (the secret weapon of the novelist) I make stuff up.
The origin of Land of Mist and Snow: A dream involving a race between a 19th c. ship and a locomotive. Plus the question, What if the Union had had a Pegasus-class patrol hydrofoil during the Civil War?
The rest is basic science-fiction/fantasy what-if extrapolation in the Secret History sub-genre. (Other clues: There was no USS Tisdale until WWII.)
