Under the President of Thomas Jefferson, Lewis and Clark began a journey from North frontier towards the western region of the US to explore the geographic features of the landscape and the people who inhabited those regions.
The expedition was significant as they discovered more than hundred specimen of biological plant life and animal kinds. They were welcomed and befriended by many native nevertheless a few had shown their unfriendliness towards them.
Their mission was to re-establish trade and business routes to India to declare American dominion.
One group can be African Americans. Racist states found ways to prevent them from voting by imposing things like laws that force you to take a literacy test or similar. They also forbade them from working like regular workers by introducing the cropsharing system.
Another can be women. Women had been fighting for their political rights since before the war began. After it ended, they were still not given voting rights which lasted up until 1920s. Many women objected how African-Americans could be given voting rights and women
Third group can be Native Americans. After the war ended, the country could then start spreading westwards which had to be halted due to the war. More states began being added and this meant that Natives would have to move to reservations and their rights and land were being taken from them.
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.
