April 16, 1818 — The US Senate today ratified the Rush-Bagot Pact — an agreement between the United States and Great Britain to eliminate their fleets from the Great Lakes.

The Convention of 1818 set the boundary between the Missouri Territory in the United States and British North America (later Canada) at the 49th parallel. 

Both agreements reflected the easing of diplomatic tensions that had led to the War of 1812 and marked the beginning of Anglo-American cooperation.

Overall relations improved, and eventually postwar trade rebounded as British political leaders increasingly viewed the United States as a valuable trading partner.

So when US Minister to Great Britain, John Quincy Adams, proposed disarmament on January 25, 1816, he got the nod from British Foreign Secretary Viscount Castlereagh.

Sources

• history.state.gov
• wikipedia/Rush–Bagot_Treaty