United States territorial acquisitions

This is a list of United States territorial acquisitions, beginning with American independence. The treaty with the United Kingdom in 1783 defined the original borders of the United States.

• The Louisiana Purchase, of 1803, was negotiated by Robert Livingston during the presidency of Thomas Jefferson; the territory was acquired from France.

• Florida Purchase, 1819, Spain, under the administration of John Quincy Adams

• Texas Annexation, of 1845: In 1836 Texas voted to be annexed by the US. Despite the fact that Mexican leader Santa Anna warned that annexation would be "equivalent to a declaration of war against the Mexican Republic," President John Tyler signed a treaty of annexation with Texas in April 1844, causing the Mexican War. After James Polk, a strong supporter of territorial expansion, won the presidency, but before he took office, Congress approved the annexation of Texas on February the 28, 1845. On December, 29th, 1845, Texas became the twenty-eighth state.

• Oregon Country, 1846

• After the Mexican War, the Treaty of Guadalupe Hidalgo, or Mexican Cession, of February 2, 1848, was signed. In this treaty, Mexico gave the United States what is now New Mexico, Arizona, and California, and recognized the Rio Grande as Texas' Southern border. The United States paid Mexico 15 million dollars. In addition, the United States agreed to pay claims made by American citizens against Mexico, which amounted to more than three million dollars.

• In the Gadsden Purchase of 1853, United States purchased a strip of land along the Mexican border for ten million dollars, now in New Mexico and Arizona. This territory was later used for the southern transcontinental railroad.

• Alaska, purchased from Russia in 1867.

• Hawaii, annexed 1896 upon the request of a government made up mainly of American settlers who had overthrown the Kingdom of Hawaii.

• Puerto Rico, Guam, and the Phillipines, taken from Spain after the Spanish-American War in 1898. The Philippines became an independent nation in 1946.

• American Samoa, occupied in 1899, made a formal territory in 1929.

• U.S. Virgin Islands, bought from the Danish Crown for 25 million dollars on January 17, 1917 during the First World War. The Virgin Islands inhabitants have become American citizens in 1927.

• Marshall Islands, Federated States of Micronesia, Northern Mariana Islands, and Palau, occupied by the United States during World War II, formalised under the UN trusteeship system in 1947. The Marshall Islands became independent in 1986 and Palau in 1994.