Why you give answer in question?
The most influential in opening the west was the transcontinental railroad. The transcontinental railroad opened up the west because it gave access to millions of citizens the opportunity to move to western states much quicker and cheaper than previous methods of transportation. Along with this, the railroads allowed for easier trading making it so that westerners could easily sell their goods to national markets.
In a very simple way, a bill becomes a law by first being introduced by a member of congress. The representative or senator discusses this in a committee, it moves to discussion in the Senate or House of Representatives for discussion. Both have to vote on the bill. If it is yes, it can be revised through further discussion before being signed by the President, then it goes on to be signed into law by the President and becomes law.
