Term originated by newspaper editor
John O’Sullivan in
1845
Merging of political and economic goals
Many people supported expansion through any means necessary
James K. Polk - Democrat
“Dark horse” candidate
Congressman from
Tennessee
Supported manifest destiny
Occupy Oregon to the 54°
40’ parallel
Annex Texas as a slave state
Territory split at the
49 th parallel to avoid war with
Great Britain
Used the existing border and drew it to the Pacific
Ocean
One of Polk’s campaign slogans – “Fifty-four forty or fight!”
Northerners opposed annexation of Texas
Annexation by a jointresolution passed in the
U.S. Congress in Dec.
1845
Border dispute ensues
U.S. – Rio Grande River
Mexico – Nueces River
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Polk sent diplomat John
Slidell to Mexico to negotiate
Offered $25 million for
California, the New Mexico territory, & Rio Grande as the Texas border
President of Mexico refused and broke off diplomatic relations
General Zachary
Taylor order to march beyond the Nueces
River
Camped at the Rio Grande
In April 1846, Mexican soldiers crossed the
Rio Grande River & attacked
Polk and his cabinet saw the attack as an act of war
“…invaded our country and shed
American blood on American soil.”
Congress declared war on May 11,
1846
Northerners called it American aggression against a weaker neighbor to extend slavery
Illinois congressman Lincoln claimed the spot was clearly in Mexico
Gen. Taylor invaded northern Mexico
General Winfield
Scott invaded Mexico
City from the Gulf of
Mexico
Gen. Stephen
Kearny marched west and captured
Santa Fe, and supported revolt in
California
John C. Fremont leads the Bear Flag
Revolt by Americans in California
End of the war
Signed at Basilica of
Guadalupe at Villa
Hidalgo
Rio Grande is the southern border of the U.S.
Mexico recognized Texas as part of the U.S.
Paid $15 million for
California and New Mexico territory
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Anti-slavery
Democrats formed this party
Because of Polk’s failing health and because he had accomplished all he wanted in one term, he did not seek reelection
Southerners desired a flat land for a southern transcontinental railroad
Wanted to link southern land to the
Pacific
Gadsden Purchase
In 1853, purchased from Mexico for $10 million dollars
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