The US was more focused on competing for resources and new markets during this era. Concerns for the US were the economic situations of the Pacific and Caribbean, along with the strategic importances of these areas. Imperialism was inevitable with the growth of industry. In need of materials, countries would take control of other lands. Ethno-centrism became a part of the European state of mind. They felt driven to impose European beliefs and ideas on the conquered territories. This was deemed the "White Man's Burden" by Rudyard Kipling, who was very much against this movement. India was very affected by Europe.
Europeans created a scramble for Africa and formed spheres of influence in China. Today, imperialism is much subtler, often in the form of foreign aid to create favorable relations between the two countries.
Many nations benefited from imperialistic practices in that they provided an opportunity to modernize. Much of the infrastructure, educational facilities, and hospitals in these countries were built by the imperialist nations controlling them. Along with the positive changes came negative. People were repressed and their cultures were left behind. Because of this, the nationalist movement was sparked. An example of this would be the peaceful revolution led by Gandhi.
Imperialistic practices led to global bitterness towards major countries. In time many of the weaker nations gained independence , and still today their is much resentment towards the former colonial powers. World War I was spawned by greed as nations competed for land and markets.
My teacher was my main resource for this, along with my father. LOL