Answer:
The transcontinental railroad became the gateway to the West. In 1862 the Republican-led Congress appropriated vast areas of land that railroad companies could use to lay their tracks or sell to raise funds for construction.
I believe the answer is rooting
Rooting refers to the type of characteristic that automatically implanted in our brain ever since we brain. (such as how to cry, how to turn heads, how to sleep,etc) The infants would automatically turn their head toward source of stimuli in order to obtain nutrients that are necessary for their survival.
The causes of the growth and decline of civilizations, and their
expansion to a potential world society, are complex. However,
civilizations require not only external advances to prosper, but also
the maintenance and development of good social and ethical relationships usually grounded in religious and spiritual norms.
