The locations of Federal Reserve District boundaries, and of the Banks within the Districts, were determined mostly by the geographic distribution of the U.S. population at the time the Federal Reserve System was created (1913), to accommodate local needs.
Mr Trump claims the total cost of the wall will be $10bn (Â£7.5bn) to $12bn. But estimates from fact checkers and engineers seem to be universally higher. Senate Majority Leader Mitch McConnell estimated it will cost between $12-15bn, as he addressed reporters at a Republican conference in Philadelphia.
There's one more aspect to Trump's plan that could make it even costlier â he is talking about a wall, not a fence. If he really means what he says, the price would go up quite a bit, Rosenblum said. The existing border wall is actually fencing and, in some areas, not even fencing but vehicular barriers.