Why is it necessary for the two superpowers to use nuclear weapons as the weapon of choice to demonstrate strength , especially during the cold war

Because nobody wants to get hit by one. If one fires, the other would fire back, causing a chain reaction. Its used to intimidate and show how much damage they could do if provoked/attacked.

False gulids were what you were so no it is false you dumb

The transcontinental railroad provided a means of fast transportation. it cut a 6 month trip into 6 days, created jobs for many people and encouraged immigration. the homestead act played a huge role in western expansion; it allowed settlers to begin a fresh start, and gave them land in exchange for their residence for up to five years and a small fee.