Final answer:
Americans were concerned about European spheres of influence because they saw them as a potential threat to U.S. security and economic interests. The United States also had a tradition of avoiding conflicts in Europe and believed that entangling alliances could jeopardize their sovereignty. Additionally, American businesses and consumers benefited from the trade generated by European peace and the expansion of the transatlantic economy.
Step-by-step explanation:
Americans were concerned about European spheres of influence for several reasons. Firstly, each new territory acquired by a foreign power within the waters surrounding the United States was seen as a potential threat to U.S. security and economic interests. Secondly, the United States had a long tradition of avoiding being drawn into conflicts in Europe, and they believed that entangling alliances with European powers could jeopardize their sovereignty. Lastly, American businesses and consumers benefited from the trade generated by European peace and the expansion of the transatlantic economy.