Many Americans opposed imperialism but few prominent were George S. Boutwell, Erving Winslow, and Edwin Buret and many more.
Explanation:
Many prominent leaders of the United States of America opposed imperialism. Generally the term anti-imperialists is used to describe those people who were against imperialism.
Being against imperialism meant those people who opposed the idea of American colonies built especially after the Spanish war.
Many anti-imperialists rejected the idea of a separate league for the anti-imperialists. The league was formed in Boston around late 1800's.
