It would be difficult for the United States for two reasons, the fact that none of the land was mapped other than the areas that previous voyagers had gone through, and the natural landscape of the area, and last, Native American Hostility.
Three examples: When pioneers would voyage to the west, there would often be encounters were they would be attacked by animals that had not been seen before, bears, sneaks, different wolves, and many more. They barely knew the natural resources of the area, such as food, etc.
The next example, no mapping, would be difficult because for the most part, they had no sense of navigation except for the few maps that had been made, even then, would be difficult to navigate.
Native Americans did not appreciate the pioneers coming into the land they considered their own, they resembled hostility and would even kill the civilians that would travel through the land, or capture them.
Hope this helps!! <3
Minorities have become quicker than the white population.
This has been true in the United States since the 1960s.
D. To take the holy land back from the Islamic empires
Corruption of the Russian Monarchy, Low resources during WW1, and public opinion.