B) The mining and cattle ranching industries increased in the West.
Railroad made transporting resources and goods to cities to be manufactured and processed which encouraged growth in the western industries.
Mining for gold, silver, iron, and tin contributed to production of manufactured goods. The ability to make money off of the mining industry attracted settlers. Ranching also increased in production with land opening up in the southwest and railroads connecting ranching areas to major meatpacking cities, like Chicago.
The general consensus amongst historians is that the balance between Federal and State powers was done to appease those who were afraid that too strong of a federal government would be no different than the monarchy that the colonists were overthrowing.
The large land was isolated from the rest of the world by deserts oceans and mountains which enabled them to develop independently from other civilizations
