Final answer:
America gained the right to navigate the Mississippi River and secured the 31st parallel as its southern border through the 1795 treaty with Spain, known as Pinckney's Treaty.
Step-by-step explanation:
The America gained significant benefits from the 1795 treaty with Spain, known as Pinckney's Treaty or the Treaty of San Lorenzo. Through intense negotiations, the United States secured the 31st parallel as the southern border of the U.S. and the right to navigate the Mississippi River freely, which was vital for Western expansion and commerce. The treaty represented a successful diplomatic effort to resolve ongoing tensions with Spain, allowing American settlers to access important trade routes and establishing a stable boundary line.
Additionally, the treaty allowed American goods to pass through the Spanish-held port of New Orleans, facilitating commerce and contributing to the economic growth in the western frontiers. With the ratification of this treaty, the United States bolstered its territorial integrity and economic access in a significant cohort with Jay's Treaty, further solidifying the young nation's international presence and expanding its reach for future growth.