MoPac very much "enjoyed" the 1901s, but they needed more HP; hence the rebuilds.
MoPac was the ORIGINAL Pacific RR, and,, unlike the UP/CP, it was already under construction during the War, but that very feature delayed it (as did a great deal of Congressional hem-hawing and investor chicanery). The road was vital to the Federal Gov't, but it was damaged physically and financially, stunting its growth. But the route was surveyed to the Pacific (eventually built upon by other roads).
