Earlier quoted context omitted.
What is the center of the US anyways? Does it include Alaska and Guam?
Great question! Is it the center of a convex hull containing the extent of territories? Or would you weight it by population? Is it in two dimensions on the surface of the Earth, or in three dimensions? Consider the possible “center” of France. There’s probably some village in France proper with a monument, but unless you eject Guiana and Réunion I think it must be in the Atlantic somewhere.
Also, this is a map game, so for me it's pretty intuitive that it is the center of the hull. Maybe with some error due to projection (not sure how they implemented the map), but should not be a problem for solving the puzzle.