The fort is part of a national historical site and has been since 1952.
Christiansted, one of the two main cities on St. Croix, was the capital of the Danish West Indies in the late 18th and early 19th centuries.
The fort was originally built in 1738. The drawing I have included I found on the internet (Wikipedia) and it was made of the fort in 1836.
So there you have it, your history lesson for the day. No go out there and conquer the world!