This has got to be one of the more understated analysis I’ve seen in a long time. For example, East of the Mississippi, movement by water had long be the fastest practical means of transport. West of the Mississippi, forget it, you have to go overland.
To further complicate things, westward expansion might have been through wilderness, but it often had a destination: the West Coast. Between the British and the Spanish, what is now Texas, the southwest, California and the Pacific northwest were places, destinations, to travel to.
A lot more people wanted to go there than stop in the Great Plains. The degree of difficulty for starting fresh was very high, evidenced by the Mormon settlement of Utah—they almost starved. They probably survived by being able to provide supplies, at a price, to settlers passing through, eventually being able to support themselves.
Only technology such as the railroads and the windmill allowed for much of the Great Plains to be occupied at all. The windmill to get water to grow crops, and the railroads to transport those crops once grown.
While certainly life by today’s standards was utterly awful on the eastern seaboard, by the standards of the day it was luxurious compared to setting out on your own across the frontier.
Much of the West only opened up after the post-Civil War, Indian Wars forced the deployment of much of the Union Army West. Once the Army was there, settlers finally had an interior place to go.
Texas was an “odd man out” for much of this, as were the Oklahoma Indian territories. They had their own paradigms of expansion and growth. The great rush to occupy them as home stakes, granted by the US government, could only happen in due course.
Texas, especially, for a while was carved up by enormous ranches like the XIT (for “Ten (Counties) in Texas”), who engaged in shameless land grabbing and exploitation. But the great cattle drives to Kansas City only lasted a short while before being ended by barbed wire fences.
As more infill happened, the primary concern of the settlers was creating a civilized town for themselves and their children. This ended many of the antics surrounding frontier settlement, culminating in the Census of 1890, which was no longer able to determine a “line” of settlement. This meant that westward expansion and the frontier were finished. It all was settled. From there it was just a matter of growth.
I suppose somewhere on the net, there are statistics showing economic output from the losers of the CW dropping to ?