Prosperity.
Calvin Coolidge was in office as president from 1923 to the spring of 1929. In that period of the "Roaring Twenties," the country experienced great economic success -- in between the brief depression that followed World War I and the Great Depression that began with the stock market crash that occurred in the fall of 1929.
Natural elements of the ecosystem are often borderlands, for example rivers or mountains, the Great Lakes.
Republic of Texas.
Texas was not a state yet and the Alamo had not occurred yet, and the borders were only created after the war was over
C because that is the only one that makes sense
Ethnic tensions made the region vulnerable to conflict.
