Expansion of the United States
Today, Americans unanimously accept the present territorial boundaries of the continental United States.
That was not always the case. Opponents of expansion objected to the acquisition of each piece of land.
However, the dominant theme in the country’s past has always been expansion. Research each of the
following acquisitions of the United States, and complete the chart below to show how the United States
accomplished this expansion to the Pacific.
Territory
Date Acquired
Previous Owner Circumstances of Acquisition
Original
United States
1783
Great Britain/
Native Americans
American Revolution. Treaty of Paris, 1783. Britain
recognizes the new U.S. to the MS River.
Louisiana
Purchase
1803
France/Napoleon
France agrees to sell to the U.S. the Louisiana Territory
which includes New Orleans. $15 Million. Doubles the
size of the U.S.
British
Cession
1818
Great Britain
Great Britain cedes (gives up) territory bordering Canada
and the United States. Rush-Bagot Treaty. British Cession.
Florida
1819
Spain
Spain cedes Florida to the U.S. Adams-Onis Treaty after
Andrew Jackson “invades” Spanish Fl. Treaty also
establishes border between US and Spanish Mexico
Texas
1845
Mexico
After independence, Texas asks to become a U.S. state.
The U.S. annexes TX.
Oregon
Country
1846
Great Britain
Previously jointed controlled by US and Great Britain.
Decide to make a permanent border extending to the Pacific
at the 49 parallel.
Mexico
War with Mexico. Treaty of Guadalupe Hidalgo cedes to
the U.S. CA, NM, UT Territories for $15 million. Mexican
Cession.
Mexico
Mexico agrees to sell to U.S. for $10 million to build a
railroad. It also settled territory boundary issue between the
two countries
Mexican
Cession
Gadsden
Purchase
1848
1853