US Territorial Expansion

Why did the US expand?

• Manifest Destiny: It was the destiny of the US to extend from the Atlantic to the Pacific. Jefferson dreamed of an “empire of liberty.”

• Monroe Doctrine (1823): No interference by European countries in the Western Hemisphere would be tolerated.

Land Additions• New States: States ceded (gave up) land to

federal gov’t. Ex: NC ceded present-day TN. New states formed: ME, VT, OH, IN, IL, MS, KY, WI, & MI.

• Louisiana Purchase• Adams-Onis Treaty (1819): Spain ceded Florida

and gave up claims to Oregon Territory.• Oregon Territory: “Fifty-four, Forty or Fight!”

Pres. Polk’s campaign slogan concerning fighting the British for this boundary line.

Louisiana Purchase

• Pres. Jefferson bought from France• Gave US land west of Mississippi Rv.• Doubled the size of the US• Hired Lewis & Clark to explore land and develop a

route west (Oregon Trail)• Sacajawea guided the explorers

Annexation of Texas

• TX became its own country (Lone Star Republic) after gaining independence from Mexico (“Remember the Alamo!”)

• US annexes (takes over) TX b/c a lot of white Americans moved there, although many NA & Mexicans there too

• Problem: Will Texas enter as a free state or slave state?

Mexican-American War

Causes• Annexation of TX• Pres. Polk opportunity to gain land

Effects• Treaty of Guadalupe-Hidalgo: US got land (CA,

NV, UT, etc.)• Gadsden Purchase: US bought part of NM & AZ

California (1849)

• “Forty-niners”: People who came to CA during the gold rush.

US Territorial Expansion