APUS Ch. 12 Amsco Notes
Territorial and Economic Expansion (1830-1860)
1845: John L. O’Sullivan coined the term “Manifest Destiny”, which became the
rallying cry for westward expansion. Looked to spread to the
Pacific in the West, Mexico, Cuba and Central America to the South.
*Believed the US had a DIVINE MISSION to extend its power and civilization across
North America. Became even more popular in the 1840’s:
 Nationalism
 Population increase
 Rapid economic development
 Technological advances
 Reform ideals
Not everyone was behind this school of thought: northern cities felt southerners were
trying to spread slavery to western lands.
I.
Conflicts over Texas, Maine and Oregon
US interests in these areas were largely due to pioneers who migrated here in the 1820’s
and 30’s. (Texas was a Mexican Province; the British claimed Oregon)
A. Texas: in 1823, Mexico won its national independence from Spain and
was now trying to recruit American settlers to the land. Moses Austin, a
Missouri banker, hoped to bring families in to the area but died. His son,
Stephen Austin, succeeded and brought about 300 families into the Texas
area. By 1830, Americans (white farmers and black slaves) outnumbered
the Mexicans in Texas by 3-1.
In 1829 friction between Americans and Mexican’s grew. Mexico outlawed slavery and
ordered immigrants to convert to Roman Catholicism. Many settlers refused to obey this.
Now, Mexico punished new American immigrants, but land hungry Americans still kept
going to Texas.
1. Revolt and Independence:
1834: General Antonio Lopez de Santa Anna made himself dictator and abolished the
federal system of government. Santa Anna insisted on enforcing Mexico’s laws in Texas.
A group of Americans led by Sam Houston, revolted and declared Texas to be an
independent republic (March 1836)
-Santa Anna led his Mexican army and captured Goliad and attacked the Alamo in San
Antonio, killing all the American defenders. Soon, a Sam Houston led army, captured
Santa Anna at the Battle of the San Jacinto River.
-Under threat of death, Santa Anna was forced to sign a treaty that recognized Texas’
independence and granted the new republic all territory north of the Rio Grande River.
But the Mexican legislature rejected the treaty and said Texas was still part of Mexico.
2. Annexation Denied
-as the 1st President of the Republic of Texas (Lone Star State), Houston applied to the
US gov’t for his “country” to be annexed to the US. As a new state. Jackson, Van Buren
and Tyler (who favored it, but Senate denied it) all denied annexation. (The threat of a
costly war with Mexico was a major concern)
B. Boundary Dispute in Maine
-a diplomatic issue b/w the boundary of Maine and Canada.
Aroostook War “battle of maps” led to the Webster-Ashburton Treaty in 1842. (Sec. of
State Daniel Webster and Br. Ambassador Lord Alexander Ashburton)
The disputed territory was split b/w Maine and British Canada. The treaty also settled the
boundary of the Minnesota Territory, leaving the iron rich Mesabi Range on the US side
of the border.
C. Another US/BR dispute involved Oregon
-By 1844, many Americans believed that it was our “Manifest Destiny” to take
undisputed possession of all of Oregon and to annex Texas as well. Expansionists also
wanted Mexico to give up California.
D. Election of 1844
-Democrats were divided: North supported Van Buren (opposed to annexation of Texas)
South supported John C. Calhoun (pro-Annexation)
This dispute led to a “dark horse” candidate. James K. Polk of Tenn. He was committed
to both expansion and manifest destiny. He also favored Texas annexation,
“reoccupation of all of Oregon” and the acquisition of California. His slogan was “54 40
or Fight” (latitude line of the border b/w Oregon Territory and Russian Alaska)
The Whigs nominated Henry Clay
RESULT: Polk wins and now people feel we must add Texas to the Union.
E: Annexing Texas and Dividing Oregon
-Before Tyler left office, he persuaded both Houses to pass a joint resolution for Texas
Annexation. He left Polk the problem of dealing with Mexico’s reaction.
-Polk compromised with Britain concerning Oregon. Both sides agreed to divide the
territory at the 49th parallel and US gave Br. Vancouver Island (ratified June 1846)
II.
War With Mexico
Texas annexation quickly led to trouble with Mexico. In 1845, Pres. Polk made John
Slidell his special envoy to the gov’t in Mexico City. Polk wanted Slidell to:
 Persuade Mexico to sell the California and New Mexico territories to the US
 Settle the Mexico-Texas border issue
Slidell’s mission failed on both counts. Mexico refused to sell California and they said
Texas/Mexico border was the Nueces River, not the Rio Grande.
A. Immediate Causes of the War
-Polk ordered General Zachary Taylor to move his army toward the Rio Grande across
claimed Mexican Territory.
April 24, 1846: a Mexican army crossed the Rio Grande and captured an American army
patrol, killing 11. Polk used this to prepare his war message to Congress. Even though
Northern Whigs protested, a large majority of both houses approved the resolution.
B. Military Campaigns
-Mostly fought by small armies of Americans
General Stephen Kearney took Sante Fe and Southern California
June, 1846, John C. Fremont proclaimed Cal. as an independent republic with a bear on
its flag (Bear Flag Republic)
Taylor’s troops crossed the Rio Grande and won the big battle at Buena Vista (Feb. 1847)
in northern Mexico.
-Polk chose General Winfield Scott to invade Central Mexico and they successfully took
Vera Cruz and Mexico City in September of 1847.
C. Consequences
-Mexico now had to agree to US terms
1. Treaty of Guadalupe Hidalgo: Mexican Cession (1848).
Negotiated by US diplomat Nicholas Trist
-Mexico to recognize the Rio Grande as Texas’ southern border
-US to take California and New Mexico-the Mexican Cession for $15 million and assume
the claims of American citizens against Mexico.
In the Senate, the Whigs opposed this treaty b/c they saw the war as an immoral
effort to expand slavery. Finally ratified by 2/3 vote in the Senate.
2. Wilmot Proviso: 1846, Penn. Congressman David Wilmot
proposed a bill to forbid slaves in any new territory acquired
from Mexico. Passed twice in the House, failed in the Senate.
3. Prelude to Civil War: led to new sectional tensions; the north
viewed the new territory as opening up more slave areas
D. Manifest Destiny to the South
Early 1850’s, many southerners now wanted to expand to Latin America especially Cuba
9use slaves on the plantations)
1. Ostend Manifesto: Polk offered Spain $100 million for Cuba, but Spain refused.
Some southerners attempted to take it, but all were caught and executed by
Spanish firing squads.
1852: Franklin Pierce is now President. He adopted pro-southern policies and sent 3
US diplomats to Ostend, Belgium, where a secret treaty was set up to buy Cuba from
Spain. The Ostend Manifesto was leaked to the press in the US and provoked an
angry reaction from antislavery members of Congress. Pierce was forced to drop this
scheme.
2. Walker Expedition: Southern adventurer William Walker, unsuccessfully tried to
take Baja, California from Mexico in 1853. Finally, in 1855, he took over
Nicaragua and even gained temporary US recognition in 1856. Honduran
authorities eventually executed Walker in 1860.
3. Clayton-Bulwer Treaty (1850): Over building a canal through Central America.
GB and the US agreed in this treaty not to take exclusive control of any future
canal router in Central America. Continued until the Hay-Pauncefote Treaty of
1901, which gave the US a free hand to build a canal w/out Br. Participation.
4. Gadsden Purchase: Although he failed to acquire Cuba, President Pierce
succeeded in adding a strip of land to the American Southwest for a RR. In 1853,
Mexico agreed to sell 100’s of acres of semi desert land to the US for $10 million.
Known as the Gadsden Purchase, (American ambassador to Mexico at the time)
the land formed what is today New Mexico and Arizona.
E. Expansion after the Civil War: 185501870, the Union, issues of slavery,
the civil war and postwar reconstruction would overshadow the drive to
acquire new territory. Manifest Destiny did continue to be an important
force for shaping US policy. For example, in 1867, Sec. of State, William
Seward succeeded in purchasing Alaska while we were recovering from
the Civil War.
III.
Settlement of the Western Territories
Many people bypassed the “Great American Desert” (Mississippi Valley-Pacific Coast)
and went straight to the more inviting lands on the west coast. Therefore, California and
Oregon settled several decades before people tried to farm the Great Plains.
A.
B.
C.
D.
E.
Fur Traders Frontier
Overland Trails
Mining Frontier
Farming Frontier
Urban Frontier
IV: The Expanding Economy
1840-1855 the US went through a remarkable period of economic growth
A. Industrial Technology
-after 1840, industrialization spread beyond New England
-shoes, sewing machines (Elias Howe), ready to wear clothing, firearms, precision
tools and iron products for RR’s.
-Samuel F.B. Morse-1844 (electric telegraph)
B. Railroads
-especially in the northeast and Midwest
-soon, it became America’s largest industry
-easier transportation and travel
-helped promote western agriculture
(would greatly help the north during the Civil War)
C. Foreign Commerce
 Scheduled departures now in place for shipping firms
 Demand for whale oil to light homes. Increased sharply from 1830-1860
 Improvements of ship design (Clipper Ship)
 1850’s: steamships
 1854: Commodore Matthew C. Perry went to Japan to open trade
-Panic of 1857: drop in prices, especially the Midwest farmers) increased unemployment
in the north, high cotton prices in the south