The Treaty of Guadalupe Hidalgo ended the Mexican-American War. The US acquired California, Nevada, Utah, New Mexico, and parts of Arizona, Colorado, Kansas, and Wyoming.
In the Rush-Bagot Agreement, the United States and Britain agreed to substantially demilitarize the Great Lakes boundary between the US and British Canada, with each cutting their fleets to far fewer vessels. This was the first disarmament agreement made by the United States.
Andrew Jackson marched into Florida to stop raids by Indians, fugitive slaves, and white outlaws on US territory. Jackson was appointed military governor.
At the Convention of 1818, the United States and Great Britain signed a treaty resolving boundary issues and providing for joint occupation of the Oregon country west of the Rocky Mountains.
The financial Panic of 1819, the country’s first major economic depression, produced political division and calls for the democratization of state constitutions and an end to imprisonment for debt.
In the Adams-Onís Treaty was negotiated by John Adams and the Spanish Minister to the United States. Spain ceded Florida to the United States. The treaty also established the border between Spanish territory and the US.