It was useful because it gave the people a sense for national interest and unity under a single culture, goal, belief, or whatever you may call it. The country was not unified until them and now they could all work together to keep the nation growing.
The completion of the Transcontinental Railroad greatly affected companies that made products in that it made it far easier for them to transport their goods over long distances to markets, which greatly increased profits and output.
Cerro Tololo is home to B. One of the world's largest observatories
A) revivalism - this was the whole point of the Great Awakening
