If taken to extremes, nationalism can create a great deal of international instability and violence. Extreme nationalism can lead to a sense of superiority and even militarism and aggression towards others who are not part of the nation.
Religious figures such as ministers who had different religious perspectives or ideas set up colleges around New England where they would be better able to preserve those ideas and be able to practice their specific religious thoughts and beliefs with other believers, as well as people who were interested and wanted to convert.
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It was the idea of wanting to have the individual states be more powerful than the federal government that guided the development of the articles of confederation, which is why they later proved to be inadequate and were replaced with the Constitution.