At the 1818 Convention, the United States and Great Britain negotiated three important points. The vague northern border of Louisiana Purchase was populated along the 49th parallel, from Lake of the Woods to the Rockies. The U.S. also got the right to share the fishery in Newfoundland and Labrador. And the third point of convergence was that the Oregon Country would be open to a common occupation between the British and the Americans for 10 years. The Rush Bagot Pact was an agreement between the United States and Britain to eliminate their fleets from the Great Lakes, with the exception of small patrol ships. The 1818 Convention established the boundary between the Territory of Missouri in the United States and British North America (later Canada) at forty-ninth latitude. These two agreements reflected the easing of diplomatic tensions that had led to the War of 1812 and marked the beginning of Anglo-American cooperation. M. Bagot met informally with Secretary of State James Monroe and eventually reached an agreement with his successor, Acting Minister Richard Rush. The agreement limited military navigation on the Great Lakes to one to two ships per country on each sea. The U.S. Senate ratified the agreement on April 28, 1818.

The British government felt that a diplomatic exchange of letters between Rush and Bagot was sufficient to make the agreement effective. Although the agreements did not fully take into account border disputes and trade agreements, the Rush Bagot Agreement and the 1818 Convention marked an important turning point in Anglo-American and American-Canadian relations. While the lines of sectionalism were drawn at the national level, some foreign policy issues remained open to the United States, which they had to resolve with Britain and Spain. From 1817 to 1819, the Monroe government negotiated various foreign policy issues with these two countries. In the Rush Bagot Agreement of 1817, the United States and Britain agreed on a limited naval presence on the Great Lakes, which eventually led to the demilitarization of the entire border. The spirit of this agreement has led to the tradition of an unbound border between the United States and Canada. Population growth in the North had led to a majority for the northern states in the House of Representatives. However, since the Senate was represented in the same way by each state and there was an equal number of free states and slaves, the Senate was divided on this issue. The House of Representatives passed the Tallmadge Amendment in a strict sectional vote, but the Senate rejected it, with some northern federalists joining the South in challenging Republicans. In 1824, Marshall made his last major decision at Gibbons v. Ogden, the „steamboat“ case, which concerned the regulation of intergovernmental trade.

In 1808, Robert Fulton and Robert Livingston pioneered the commercial use of the steamboat and had a monopoly on steam navigation on the Hudson River in New York City. In 1815, Aaron Ogden acquired the exclusive right to operate a ferry between New York and New Jersey. When Thomas Gibbons, who owned a federal trading license, set up a competing line, Ogden sued him. Many factors contributed to the panic of 1819, including a decline in exports and strong price competition for foreign goods. Falling prices have affected agriculture and manufacturing and caused widespread unemployment. Another major cause has been the risky granting of bank loans in the West. The second largest bank in the United States strengthened its lending policy and eventually forced these „wild“ border banks to close mortgages on countless similar farms and debtors, leading to bankruptcies and prisons full of debtors.