U.S. Territorial Acquisitions

Date	Territory	Area (square miles)	Comment
1783	Former colonies	892,135	Treaty of Paris of 1783 following military victory
1803	Louisiana Purchase	827,987	Purchased from France for $15 million, including assumed claims
1819	Florida (East and West)	72,101	Purchased from Spain for $5 million in assumed claims under Adams-Onís Treaty
1845	Texas	389,166	Annexation of independent republic
1846	Oregon Territory	286,541	The Oregon Treaty with Great Britain
1848	Mexican Cession	529,189	Purchase from Mexico following military victory; $15 million plus 3.25 million in assumed claims
1853	Gadsden Purchase	29,670	Purchased from Mexico for $10 million
1857	Baker Island Howland Island Jarvis Island	.5 .6 1.7	Unincorporated territory claimed under Guano Act of 1856
1858	Johnston Atoll	1.1	Unincorporated territory annexed under Guano Act of 1856; chemical weapon disposal site
1867	Alaska	591,000	Purchased from Russia for $7.2 million; statehood 1959
1867	Midway Islands	2	Annexation of unoccupied area
1898	Hawaiian Islands	6,450	Annexation of independent republic; statehood 1959
1898	Philippine Islands	115,800	Purchased from Spain following military victory; independent in 1946
1898	Puerto Rico	3,508	Annexed following military victory over Spain
1898	Guam	209	Annexed following military victory over Spain
1899	American Samoa	76	Annexed in settlement with Britain and Germany
1899	Wake Island	3	Annexation of unoccupied area
1903	Panama Canal Zone	553	Leased from Panama for $10 million, plus $250,000 annually; ceded to Panama in 1999
1917	Virgin Islands	136	Purchased from Denmark for $25 million; currently an organized, unincorporated U.S. territory under jurisdiction of Office of Insular Affairs of the Dept. of the Interior
1922	Kingman Reef	.4	Annexed 1922; later airline refueling; currently uninhabited; National Wildlife Refuge
1938	Kanton and Enderbury islands	3.5 3.0	Joint occupation with Britain; independent as Kiribati in 1979
1947	Mariana Islands	179	United Nations Trust Territory; self-governing as Northern Mariana Islands
1947	Caroline Islands	500	United Nations Trust Territory; 1986 most islands adopt commonwealth status as Federated States of Micronesia
1947	Marshall Islands	70	United Nations Trust Territory; 1979 self-governing; 1986 independent as Republic of the Marshall Islands