Final answer:
Secretary of State John Adams had to conduct negotiations with Great Britain to settle the northwestern boundary of the United States, leading to the formation of treaties that secured American borders and trade routes.
Step-by-step explanation:
During the 1780s and the 1790s, the United States was a new nation faced with territorial threats on all of its borders. The boundary with Canada was unclear, and Great Britain had not fully evacuated its trading posts in the Northwest despite losing the thirteen colonies and the lands east of the Mississippi in the Treaty of Paris. The Spanish government played a role in complicating the situation by disputing the southern United States border and closing the Mississippi River to American traffic. These issues led to diplomatic efforts to solidify America's frontier and international trade interests. Warfare with the Indian nations added another layer of complexity, as Britain encouraged tribal resistance to U.S. expansion.
John Adams, along with other American diplomats, had to navigate these challenges in a series of negotiations resulting in agreements such as Jay's Treaty and Pinckney's Treaty (Treaty of San Lorenzo), which were crucial in securing American borders in the West and resolving trade conflicts. Jay's Treaty sought to address the British occupation of northwest posts and trade restrictions, while Pinckney's Treaty established the U.S.-Spanish border at the 31st parallel and opened the Mississippi River to American navigation. These diplomatic efforts were essential to the United States asserting its sovereignty and establishing stable boundaries.