Territorial evolution of the United States

Table columns:
Date
Event
Change Map

Table rows:
cells: July 4, 1946
The Commonwealth of the Philippines became independent as the Republic of the Philippines.[377]
Pacific Ocean:
cells: July 18, 1947
The United Nations entrusted the Trust Territory of the Pacific Islands to the United States.[7]
Pacific Ocean:
cells: January 1, 1949
The Tokelau Islands were incorporated into New Zealand, which inherited the claims on Atafu, Fakaofo, and Nukunono.[378]
Pacific Ocean:
cells: August 1, 1950
Guam was organized into a civil territory.[379][380]
no change to map
cells: August 3, 1950
Kansas and Missouri exchanged small portions of land along the Missouri River, due to shifts in the river following a flood in 1944.[381]
cells: April 11, 1955
Panama's corridor connecting Colón with the rest of Panama was realigned within the Panama Canal Zone. Several three-dimensional "tubes" of sovereignty were also created, allowing Panamanian bridges to pass over rivers and a highway at several locations within the Canal Zone.[382][383]
too small to map
cells: August 23, 1955
Several border locations of the Panama Canal Zone were redefined. Punta Paitilla, the land held on Taboga Island, and the remaining American holdings in Colón and Panama City were ceded to Panama.[313][384]
Caribbean Sea:
cells: January 3, 1959
The Alaska Territory was admitted as the forty-ninth state, Alaska.[385]
Northwestern North America:
cells: August 21, 1959
Most of Hawaii Territory was admitted as the fiftieth state, Hawaii. Palmyra Atoll was excluded from statehood and remained a territory.[230][386]
Pacific Ocean:
cells: August 25, 1961
About 20 acres of land was transferred from Minnesota to North Dakota near Fargo, North Dakota;[176][387] since the area was very small and poorly documented, it is not mapped.
too small to map
cells: January 14, 1964
The Chamizal, a tract of land between El Paso, Texas, and Ciudad Juárez, Chihuahua, was divided between the United States and Mexico.[388]
cells: August 4, 1965
The Cook Islands became self-governing from New Zealand. It claimed the atolls of Pukapuka, Manihiki, Penrhyn, and Rakahanga.[389]
Pacific Ocean:
cells: April 25, 1971
The lease of the Corn Islands from Nicaragua was terminated.[331]
no change to map
cells: September 1, 1972
The United States recognized the sovereignty of Honduras over the Swan Islands.[331][390]
Caribbean Sea:
cells: March 1, 1977
The United States claimed maritime borders west of the Strait of Juan de Fuca, within the Dixon Entrance, and in the Beaufort Sea that conflicted with claims of Canada.[391]
no change to map
cells: May 26, 1977
Several parcels were exchanged between Texas and Mexico along the Rio Grande in areas near Presidio and Hidalgo, Texas,[392] including the Horcón Tract, on which the town of Río Rico was located,[393] and Beaver Island near Roma, Texas. In addition, Mexico ceded 823 acres (3.33 km2) to the U.S., while the U.S. ceded 2,177 acres (8.81 km2) to Mexico, primarily to straighten sections of the Rio Grande for flood control.[394]
cells: October 1, 1978
Tuvalu became independent from the United Kingdom. It claimed the atolls of Funafuti, Nukufetau, Nukulaelae, and Niulakita.[395]
Pacific Ocean:
cells: July 12, 1979
The Republic of Kiribati became independent from the United Kingdom. It claimed Birnie Island, Canton Island, Caroline Island, Christmas Island, Enderbury Island, Flint Island, Gardner Island, Hull Island, Malden Island, McKean Island, Phoenix Island, Starbuck Island, Sydney Island, and Vostok Island. This dissolved the condominium of the Canton and Enderbury Islands.[396]
Pacific Ocean:
cells: October 1, 1979
The Panama Canal Zone was ceded to Panama. The United States and Panama continued to share operational control of the canal until December 31, 1999, when it would be fully turned over to Panama.[397] The United States retained control over several hundred specified areas to be turned over in piecemeal fashion over the years.
Caribbean Sea:
cells: November 24, 1980
The maritime border between the United States and Venezuela was defined.[398]
no change to map
cells: September 17, 1981
The United States recognized the sovereignty of Colombia over Roncador Bank and Serrana Bank, and the claim on Quita Sueño Bank was abandoned by the United States, as it was no longer above the seas at high tide, and thus the government considered it unclaimable.[331][399]
Caribbean Sea:
cells: September 3, 1983
The United States recognized the sovereignty of the New Zealand territory of Tokelau over Atafu, Fakaofo, and Nukunono.[331][400]
Pacific Ocean:
cells: September 8, 1983
The United States recognized the sovereignty of the Cook Islands over Pukapuka, Manihiki, Penrhyn, and Rakahanga.[331][401]
Pacific Ocean:
cells: September 23, 1983
The United States recognized the sovereignty of Kiribati over Birnie Island, Canton Island, Caroline Island, Christmas Island, Enderbury Island, Flint Island, Gardner Island, Hull Island, Malden Island, McKean Island, Phoenix Island, Starbuck Island, Sydney Island, and Vostok Island.[331][402] The United States recognized the sovereignty of Tuvalu over Funafuti, Nukufetau, Nukulaelae, and Niulakita.[331][403]
Pacific Ocean:
cells: October 12, 1984
The International Court of Justice made its judgment on where the maritime border should be in the Gulf of Maine between the United States and Canada.[404] No land changed hands. The scope of the case did not include the sovereignty of Machias Seal Island, but the judgment enabled defining the extent of the disputed water area around that island (an area of 210 square nautical miles).[391]
no change to map
cells: October 21, 1986
The Marshall Islands District of the Trust Territory of the Pacific Islands became independent as the Republic of the Marshall Islands.[405] The Marshall Islanders had claimed Wake Island as part of their territory since at least 1973, and continued that after independence.[406]
Pacific Ocean:
cells: November 3, 1986
Most of the Trust Territory of the Pacific Islands was dissolved by the United Nations. The districts of Chuuk, Pohnpei, and Yap became independent as the Federated States of Micronesia. The Mariana Islands District, having already been taking moves towards integration with the United States, became a territory of the United States, the Commonwealth of the Northern Mariana Islands.[405]
Pacific Ocean:
cells: June 1, 1990
The maritime border between the United States and the Soviet Union was provisionally defined. The two countries agreed on this date to abide by the terms of the treaty pending its ratification and entry into force,[407] but while it was ratified by the United States Senate on September 16, 1991,[408] it is unknown if either the Soviet Union or its successor state, Russia, ratified it.
no change to map
cells: October 1, 1994
The remaining district of the Trust Territory of the Pacific Islands, the Palau District, became independent as the Republic of Palau, dissolving the TTPI.[409]
Pacific Ocean:
cells: June 1, 1995
The maritime border between the United States and territories of the United Kingdom in the Caribbean Sea was defined.[410][411]
no change to map
cells: January 16, 1997
Navassa Island was transferred to the United States Department of the Interior.[412][413]
no change to map
cells: November 13, 1997
The maritime border between the United States and Mexico was defined.[414]
no change to map
cells: December 31, 1999
All former Panama Canal Zone parcels not turned over since 1979, as well as all joint canal operations areas, were transferred to Panama.
too small to map
cells: January 17, 2001
The maritime border between the United States and Mexico on the continental shelf in the western Gulf of Mexico beyond 200 nautical miles was defined.[415]
no change to map
cells: November 24, 2009
Six islands along the Rio Grande were ceded from Texas to Mexico, and three islands and two bancos were ceded from Mexico to Texas. The transfer, which had been pending for 20 years, was the first application of Article III of the 1970 Boundary Treaty.[361][416]
too small to map
cells: September 23, 2014
The maritime border between the United States and Niue was defined.[417] The treaty was signed on May 13, 1997, but it was not ratified by the United States until at least 2002, and the United Nations shows it as entering into force on this date.[418]
no change to map
cells: January 1, 2017
The border between North Carolina and South Carolina was clarified following years of surveys and negotiation, moving 19 homes across state lines.[419][420]
too small to map

Questions about this table:
originalText: which is the most recent state to have joined the united states of america
answer: answerTexts: Hawaii