| 1800 | Thomas Jefferson and Aaron Burr tie in electoral college. Gabriel's rebellion reported. |
| 1801 | House of Representatives elects Jefferson president. Barbary War with Tripoli begins. |
| 1803 | Marbury v. Madison. United States warned not to ship war goods to Britain or France. Louisiana Purchase. |
| 1804 | U.S. defeats Tripoli. Jefferson meets with Osage Indians. |
| 1804–1806 | Lewis and Clark expedition. | 1807 | Chesapeake incident. Embargo Act. United States establishes trade with Comanche Indians. |
| 1808 | James Madison elected president. |
| 1809 | Treaty of Fort Wayne. Non-Intercourse Act. |
| 1811 | Battle of Tippecanoe. |
| 1812 | United States declares war on Great Britain. |
| 1813 | Tecumseh dies at battle of the Thames. |
| 1814 | British attack Washington City. Treaty of Ghent. Hartford Convention. |
| 1815 | Battle of New Orleans. |
| 1816 | James Monroe elected president. |
| 1819 | Adams-Onís Treaty. |
| 1820 | Missouri Compromise. |
| 1823 | Monroe Doctrine asserted. |
| 1825 | John Quincy Adams elected president by House of Representatives. |