1879-1820 U.S. history timeline By superninjakiwi Sep 3, 1783 The U.S. signs a peace treaty with the British The signing of the Treaty of Paris, in which the British recognized The United States as it's own country, and ceased war between the two countrys. Jan 1, 1791 Washington D.C. is chosen as the nation’s capital The only planned city is created. Jan 1, 1793 Eli Whitney invents the cotton gin The cotton gin is invented. Nov 19, 1794 Jay's Treaty The treaty that resolved problems remaining from the Revolutionary War between the British and U.S. citizens. Apr 30, 1803 The Louisiana Purchase The purchase of a large amount of land from the French, who sold it to The United States for less than three cents an acre. Period: May 14, 1804 to Sep 23, 1806 Lewis And Clark Expidition The journey of Meriwether Lewis and William Clark from the Mississipi River to the Pacific Ocean and back. Jan 1, 1807 Fulton develops a powerful steam boat engine Jan 1, 1808 Erie Canal is built Increased trading. Jan 1, 1811 The National Road is built to West Virginia The road built to connect all of the United States. Jan 1, 1821 U.S. gains Florida from Spain Spain sold Florida to The U.S.