Following the War of 1812, increases in wealth and population growth gave the United States the means to deal decisively to secure its borders. The immensity of the American frontier, largely unsettled, except for the seminomadic tribes, as well as the requirements of politics caused the United States to identify and achieve its continental ambitions in stages. Territorial expansion was soon perceived as a remedy for the nation's ills---a safety valve for the unfortunate and defeated, a unifying formula for political victory. The process of expansion became a shaping event for the formation of the American nation, as important as the political experiment embodied in the Constitution. But it also provided the means for the nation's most controversial institution, slavery to revive and flourish.

• 1838: Congress adopts "gag resolutions" against antislavery petitions and motions.
  
  U.S. Troops forcibly moved the Cherokee indians from Georgia, to Indian Territory in eastern Oklahoma.
  
  Some northern states passed Personal Liberty Laws which obstructed the fugitive slave act of 1793. Southern slaves developed a system of
  escape routes to the north known as the Underground Railroad.
  

• 1839: Patent issued to John Deere for his steel plow.
  
  Liberty Party, the first anti-slavery party, holds national convention in Warsaw, New York.
  
  France Recognizes Texas's Independence.
  
  Audubon publishes Birds of North America.
  
  First baseball diamond laid out in Coopers Town, New York..

• 1840: Congress passes Independent Treasure Act. Presidential election contested by Van Buren and Whig candidate General Will Henry Harrison of Indiana.
  
  The Liberty party enters the presidential race. Harrison becomes the first Whig elected as President using"Tippecanoe and Tyler too."
  
  The sixth national census shows the population of more than 17,000,000, about 600,000 immigrants have arrived in America since 1830.
  
  
• 1841: Harrison is inaugurated as president in March and dies one month later. He is succeeded by John Tyler.
  
  The Preemption Act passed by Congress.
  
  Tyler vetoed bill to charter a national bank.
  
  First pioneer settlers migrate overland to California.
  
  
• 1842: The Webster-Ashburton Treaty settled the dispute between the U.S. and Great Britain, establishing the U.S. - Canadian border from Maine to the Lake of the Woods in northern Minnesota.
  
  Congress passes the Whig tariff law with high protective levels.
  
  Ralph Waldo Emerson becomes editor of The Dial, the influential publication of the transcendentalist movement.
  
  Barnum's American Museum, opens in New York City. P.T. Barnum exhibits General Tom Thumb and other freaks, as well as many hoaxes, attracting the general public with extravagant advertising.
  
  Explorer John Fremont, leads an expedition to explore the route to Oregon, beyond the Mississippi River, as far as South Pass in Wyoming.