What was the role of the American Indians in the creation of European colonies?

Because Native Americans were the existing community of people in the Americas before the arrival of European colonizers, their presence certainly influenced the way colonization occurred. Colonization occurred in a broad manner, with the Spanish, British, Portuguese, French and other countries all seeking to establish themselves in the Americas, and each of them encountering different indigenous people groups depending on the location they were colonizing. 

The Native Americans shaped the land prior to the arrival...

Because Native Americans were the existing community of people in the Americas before the arrival of European colonizers, their presence certainly influenced the way colonization occurred. Colonization occurred in a broad manner, with the Spanish, British, Portuguese, French and other countries all seeking to establish themselves in the Americas, and each of them encountering different indigenous people groups depending on the location they were colonizing. 

The Native Americans shaped the land prior to the arrival of Europeans, and their presence also shaped the development of the newly rooting colonies. The settlers' interactions with Native Americans initially spanned a spectrum from positive to extremely negative. At first arrival, interactions could be pleasant, such as in the quintessential example of the Native Americans assisting starving colonists by providing food for them in Virginia and Massachusetts. At the other end of the spectrum, settler–Native American relations were fraught with skirmishes and bloodshed as the two groups battled over territory and access to resources. In the middle of the spectrum, settler-Native relations were business-oriented, with the establishment of trade agreements between tribes and colonies. These types of agreements greatly benefitted European settlers who, as new arrivals, were often in need of goods and information about the local land.

Early in the process of colonization, Native Americans shared resources, knowledge, and territory with the settlers. However, the two groups also fought each other viciously in certain locations. The presence of existing groups of people in the "New World" certainly made matters more complicated for the settlers, but ultimately, it could be argued that the Native American influence on colonization was a net gain for the settlers, who gained possession of the lands they desired and greatly benefitted from the goods the Native Americans had to offer. The Native Americans lost the conflict and faced grave damage to their people and their way of life. The tragedy serves as a reminder of the terrible consequences of colonization and imperialism.