The ideal place to build these things would be in the Great Lakes region so as to take advantage of the abundant fresh water (which has the added benefit of being quite cold) for cooling the new (preferably nuclear) power plants needed to run the data centers. Build a dedicated nuclear plant on the shore of Lake Michigan or Lake Superior and put a data farm next to it. Rinse and repeat.
The reason we don't do this, of course, is due to government burdens and graft burdens. It takes forever to get a new nuclear plant built due to the red tape involved. Also, business-friendly states are generally in the south, not the north, so that's where business and capital are going. So we get data centers in hot desert states like Arizona and Texas, places where the laws of thermodynamics suggests they shouldn't be at all.

The best place on the continent for data centers would be in northern Canada on the shores of their big lakes (Great Bear Lake, Great Slave Lake). The area is almost devoid of people and development due to the harsh climate, so you wouldn't be gobbling up valuable real estate. But data centers are strategic infrastructure, so realpolitik means they should be built in the contiguous 48 states, so with that in mind, I'd ideally put them in Minnesota, Wisconsin, and Michigan.
Anyway, just my two cents.
