Imperialism is a political and military philosophy in which one country or government seeks to conquer other countries and societies and bring them under the control or influence of the invading country.
Imperialism is often associated with the economic theory of mercantilism, in which the conquering country (known as the metropole) becomes the center of manufacturing and production while the conquered countries (the colonies) become the suppliers of raw natural goods. Under a mercantilist system, the point of having colonies is to enrich the metropole.
Imperialism takes a number of forms. There's settler colonialism, where a metropole established colonies to gather raw goods or resources (New York and Jamestown are examples). There's religious imperialism, in which a country invades other countries for the purposes of spreading a religion (Spain was infamous for this) or establishes religious communities abroad (as in Massachusetts Bay).
Imperialism has also existed for ages and ages. The Romans are one famous example, but virtually every country in Western Europe (France, Britain, Spain, Portugal, Germany, Belgium, etc) had an empire at one point. But so did the Japanese, the Russians, the Zulus, and the Comanches.
As famous as Marco Polo is, he didn't invent anything. However, other inventions such as the compass and the boat influenced Polo. Marco Polo used the compass on all of his travels but especially to reach Asia.
The way that Railroads helped impact migration and settlement of the american west is; It helped with means of transportation and allowed for quicker means of the transportation.
Explanation:
There were many different ways people could transport things in the American west but most of them would be slower if they didn't construct a railroad.