Some historians have gone on record stating the belief, in keeping with my own never-mentioned position, that around 1850, the improvements made to railroad use were absolutely the most-singular fact advancing the Eastern U.S. culture and economy westward to the Pacific Ocean. The first Transcontinental Line, completed in Promontory Point, Utah, I think in 1869, clinched it. After that, (and prior, given the discovery of gold at "Sutter's Mill"), it became anyone's guess whether the greater bulk of American existence would remain along the East Coast, or perhaps wind up bordering the Pacific. Investment activity was rampant at both ends, I think. But, everything from abroad came across the Atlantic, even the stuff from the Middle East, which was closer to our West Coast. Then, it had to find it's way, in bulk, to, of course, Los Angeles, (!!), via what else but rail. So, by 1900 or so, the West Coast (today referred to by many folks there as the "Worst Coast"), became wel-known for it's climate: conducive to year-round crop growing, mild winters, and more, all conducive to consideration of Southern California as Paradise. And then, it was, IMO. AFAIK, the builders of the railroads are the most important contributors to Western U.S. development. The Southwest, dry, for the most part, desert for a large part, early-on despised by Easterners, later appreciated by large numbers (too large as it turns out today) for it's challenges in addition to mild weather, has become overpopulated based upon it's ability to supply adequate fresh water. Very low annual precipitation rates, which are tantamount to fulfillment of anticipated water storage above ground, coupled with abundant deep-well groundwater availability, has encompassed the enigma of apparent "plenty of water", with that of "drought-induced" shortage. The "linchpin" which could bail-out the water-induced economic crises looming on the horizon would be cheap seawater desalinization. Not yet developed, though. Blame the railroaders. Or the money-mongers. Or the greedy politicians. Or, Mother Nature. Or chance, as determined by the spinning "policy-wheel". Or ourselves. Cut to the "chase", drastic change is coming, inevitably, unless Ma Nature offers a short reprieve, after which it will relentlessly return to present our near-future generations with technical obstacles of historical precedence.