Who were the first victims of american imperialism?

The first true victims of American Imperialism were the Native Americans. As settlers slowly pushed West, native peoples were killed, forced out, or forced to assimilate into White American culture. Land would be set aside to "house" these many peoples, but even that would soon be settled. Native lands were slowly chipped away until they look as we see them. Many groups went from hundreds of thousands of miles of territory to a few hundred acres. Sometimes the land they were "given" wasn't even in their ancestral homeland, but thousands of miles away. Around the same time Americans would rob many Mexicans of the lands that they had settled and farmed for generations. 

Ummm they were radical