It should be remembered that the Federalists and Republicans had not yet developed into parties by 1795, when the treaty was signed. Thomas Pinckney himself was aligned with the emerging Federalist faction, so the treaty that bears his name (also known as the Treaty of San Lorenzo) was popular among Federalists, and in fact increased their popularity outside of the Northern states from which they drew most of their support. The main concession made by Spain in the treaty, the right to free navigation of the Mississippi, was a boon to settlers who were beginning to pour across the Appalachians into the West. They needed access to the river, and to New Orleans, to transport their crops to market. A previous treaty with Spain, the Jay-Gardoqui Treaty, had failed to guarantee this right. While the West would fall solidly in the Jeffersonian Republican camp over the next decade or so, Pinckney's Treaty was a large step toward securing the loyalties of Western settlers to the United States, and this was hardly a given in the late eighteenth century. It also secured the borders of the United States with Spain. For all these reasons, Pinckney's Treaty was popular with Federalist-leaning politicians as well as with most Americans.