Final answer:
Congress feared the violation of American sovereignty by Britain, which included the impressment of sailors and interference with trade. This led to the War of 1812 to defend national integrity and avoid a decline in international prestige.
Step-by-step explanation:
During the period leading up to the War of 1812, Congress feared the violation of American sovereignty as a primary reason for going to war with Britain. This concern was due to a number of provocations, including the British practice of impressment of American sailors into the Royal Navy, interference with American shipping, and support for Native American attacks on American frontier settlements. There was also a fear that if the United States did not stand up to these British practices, it would suffer a decline in international prestige and signal a weakness that could encourage further violations of American rights and territory. Additionally, ongoing issues with British and Spanish trade policies and territorial disputes highlighted vulnerabilities in American foreign policy and commercial capabilities, as individual states within the Confederation had the power to make their own decisions, often to the detriment of national unity and strength.