President Andrew Jackson signs a law enabling the forced relocation of Native American nations west of the Mississippi, leading to the Trail of Tears.
Mexican troops under General Santa Anna storm the Alamo in San Antonio, killing its Texan defenders; the battle becomes a symbol of the Texas Revolution.
President James Monroe declares that the United States will oppose any further European colonization or intervention in the Americas.
Samuel Morse sends "What hath God wrought" from Washington to Baltimore, inaugurating long-distance electric telegraphy.
War between the United States and Mexico following the US annexation of Texas; Mexico is defeated and loses about half of its territory.
At Massachusetts General Hospital, William Morton anaesthetises a surgical patient with ether in public, opening the era of surgical anaesthesia.
The United States declares war on Britain; fighting in North America and at sea ends with the Treaty of Ghent and no change in borders.