The Early National Period of the U.S. marks the nascent stages of the United States post-Revolution. Beginning with the shortcomings of the Articles of Confederation, the nation adopted the more robust U.S. Constitution in 1788, establishing a strong federal system. Under George Washington’s precedent-setting leadership, the country began to define its political landscape, seeing the rise of Federalists and Democratic-Republicans. The nation’s territorial expansion was amplified with the Louisiana Purchase in 1803. Tensions with Britain culminated in the War of 1812, ending with increased national pride and setting the stage for the subsequent “Era of Good Feelings.”