Territorial Expansion
The United States in 1783
A “territory” is a land area that has not yet been divided into states. In 1783 the
United States received a huge territory from Great Britain as part of the peace treaty ending
the revolutionary war. This new region stretched from the Appalachian Mountains to the
Mississippi River, and from Canada to Spanish Florida. No additional land was acquired by
the American government during the next 20 years. Then, from 1803 to 1853, seven more
territories were added to the country. These acquisitions fulfilled the “manifest destiny” of
the United States – that is, the belief that the nation should expand to the Pacific coast.
Louisiana Purchase (1803)
1801: France obtained the Louisiana Territory from Spain. When New Orleans belonged to the Spanish,
American farmers in the West were allowed to ship their goods through the city to the eastern United States
and Europe. But the French, under the leadership of Napoleon, denied use of the Mississippi River and the
port at New Orleans. There was a growing concern in the United States that Napoleon would try to establish
a powerful empire in North America.
1803: President Thomas Jefferson sent representatives to France in an attempt to
get permission to use the Mississippi River and port facilities at New Orleans.
Napoleon surprised the Americans by offering to sell New Orleans and the whole
Louisiana Territory for $15 million dollars. The Louisiana Purchase Doubled the
size of the United States
1804-1806: Meriwether Lewis and William Clark explored the Louisiana Territory. They traced the Missouri
River to its source in the Rocky Mountains, then followed the Columbia River to the Pacific Ocean.
(To learn more about the Louisiana Purchase and the Lewis and Clark Expedition click here)
Land above the Louisiana Purchase (1818)
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Great Britain at the time owned Canada. The British
land in dispute. The United States was given a small
and American governments both claimed land along
area just above the Louisiana Territory. Great Britain
the boundary between Canada and the Louisiana
received a small piece of land farther north in what is
Territory. Finally an agreement was reached about the
now Canada.
Spanish Cession (1819)
1818:Florida had been under Spanish Control since the expedition of Ponce de Leon in
the 1500’s. By the early 1800’s it had become a trouble spot for the United States.
Hundreds of runaway slaves went there. The Seminole Indians of Florida often crossed
in to Georgia and attacked American settlers. President James Monroe sent General
Andrew Jackson to drive the Indians out of Georgia. Jackson chased the Seminoles into
Florida and captured two Spanish forts.
1819: Spain saw that it was unable to defend Florida against an American invasion.
Spain at the time was busy trying to put down revolutions in its Latin American colonies.
So the Spanish agreed to give up the area if the United States would pay American
citizens $5 million dollars that was owed to them by Spain. The land included Florida
and parts of Alabama, Mississippi, and Louisiana.
Texas Annexation (1845)
1822: Mexico decided to open Texas to American settlers. Stephen Austin led the first American
families into Texas.
1830: Mexico became worried about the flood fo immigrants from the United States, and banned
further settlement. The Americans and Mexicans differed in Language, religion, and ways of
living. The Mexican government passed a law saying American plantation owners could no
longer own slaves, but the
law was ignored.
1835: Santa Anna became
and warned that American
laws.
U.S. settlers who moved
1836: Texas declared its
Mexico. Santa Anna led a
Texas. Several thousand
surrounded 187 American
San Antonio. William
Bowie, and other Texans
Texas’ independence from
into Texas declared
Mexico. However, Mexico
would launch a long battle
at the Alamo before
allowing the territory
its
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independence.
the president of Mexico
settlers must obey Mexican
independence from
Mexican army north into
Mexican soldiers
at the Alamo, a mission in
Travis, Davy Crockett, Jim
fought a courageous 2
week battle before being killed. Gerneral Sam Houston was name commander of the Texan
army. The battle ry became “remember the Alamo.” General Houston defeated Santa Anna at he
Battle of San Jacinto, and the Texas Revolution came to an end.
When Texas won its independence from Mexico, it asked Congress to be admitted to the Union
as a state. The northern states opposed this request because many slave owners lived in Texas.
Others feared a war with Mexico. Congress decided against statehood, and Texas remained an
independent country known as the Lone Star Republic. Sam Houston was elected President of
the new nation.
1845: After a lengthy debate in Congress, Texas was admitted to the Union as the 28th state.
Oregon Country (1845)
1818: The United States and Great Britain agreed to the “joint-occupation” – shared ownership
– of the Oregon Country. Persons from either country could settle there. The Oregon Country
included land that is today part of Canada. For many year Indians and fur traders were the
only people living in the region.
1836: Marcus and Narcissa Whitman and other American missionaries went to the NorthCountry. They wanted to help the Indians and spread Christianity to the North west.
1843: The Whitmans told people back east about the rich farmland in Oregon, and many
pioneer families began moving there. They traveled together in wagon
trains fro protection against the Indians. The Oregon Trail stretched for
2,000 miles from Independence Missouri to the Willamette Valley of
Oregon.
1844: James K. Polk used the slogan “54-40 or fight!” during his campaign for president.
1846: The United States and Great Britain agreed to divide the Oregon Country into two parts.
The United States was given the southern half, and Great Britain took control of the northern
half. The boundary line was the 49 degree latitude line.
Mexican Cession (1848)
1845: Texas was admitted to the Union. This angered Mexico which still considered Texas to be its
territory.
1846: A boundary dispute arose between the United States and Mexico. Both countries claimed an area
of land between northern Mexico and southern Texas. The United States said the boundary line was the
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Rio Grande. The Mexicans claimed it was the Nueces River. The dispute led to the outbreak of the
Mexican War.
1846-1848: General Zachary Taylor defeated Santa Ana at the Battle of Buena Vista. Colonel Stephen
Kearney marched to California and helped American settlers overthrow the Mexicans in the Bear Flag
Revolt. General Winfield Scott captured Veracruz and Mexico City, and Mexico surrendered.
1848: The United States won a large land area that today makes up the southwestern part of the United
States. The United States paid Mexico $15 million for this area, known as the Mexican Cession.
Gadsden Purchase (1853)
1853: Congress was studying four possible routes for building a transcontinental railroad to the Pacific coast.
Supporters of a southern route wanted to extend the railroad at New Orleans westward to California. They
pressured Congress into spending $10 million for a small strip of land and the southern end of the Rocky
Mountains which would provide a level route to the west coast. The Gadsden Purchase, as the land area
was called, was obtained from Mexico by foreign minister James Gadsden. The Gadsden Purchase, now part
of southern Arizona and New Mexico, completed the acquisition of land that today makes up the continental
United States.
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Territory
Country Obtained
Year Obtained
Approximate Cost
from…
U.S. in 1783
Britain
1783
Revolutionary war victory
Louisiana Purchase
France
1803
15 million
Spanish Cession
Spain
1819
5 million
Texas Annexation
Mexico
1845
NA
Oregon Country
Britain
1845
NA
Mexican Cession
Mexico
1848
15 million
Gadsden Purchase
Mexico
1853
10million
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Contents
The United States in 1783 ............................................................................................................................. 1
Louisiana Purchase (1803) ............................................................................................................................ 1
Land above the Louisiana Purchase (1818) .................................................................................................. 1
Spanish Cession (1819) ................................................................................................................................. 2
Texas Annexation (1845) .............................................................................................................................. 2
Oregon Country (1845) ................................................................................................................................. 3
Mexican Cession (1848) ................................................................................................................................ 3
Gadsden Purchase (1853) ............................................................................................................................. 4
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