| Long title | An Act to authorize Protection to be given to Citizens of the United States who may discover Deposits of Guano |
|---|---|
| Enacted by | the34th United States Congress |
| Effective | August 18, 1856 |
| Citations | |
| Public law | Pub. L. 34–164 |
| Statutes at Large | 11 Stat. 119 |
| Legislative history | |
| |
TheGuano Islands Act (11 Stat. 119, enacted August 18, 1856, codified at48 U.S.C. ch. 8 §§ 1411-1419) is aUnited States federal law passed by theCongress that enablescitizens of the United States to take possession of unclaimed islands containingguano deposits in the name of theUnited States. The islands can be located anywhere, so long as they are not occupied by citizens of another country and not within the jurisdiction of another government. It also empowers thepresident to use the military to protect such interests and establishes the criminal jurisdiction of the United States in these territories.

In the 1840s,guano became a prized agriculturalfertilizer and source ofsaltpeter for gunpowder.
The U.S. began importing it in 1843 through New York. By the early 1850s, the U.K. imported over 200,000 tons a year, and U.S. imports totaled about 760,000 tons.[3] The "guano mania" of the 1850s led to high prices in anoligopolistic market, government attempts tocontrol prices, fear of resource exhaustion, and eventually the enactment of theGuano Islands Act of 1856 in August 1856.[4] The Act authorizes U.S. citizens to take possession of unclaimed islands containing guano for the U.S., empowers the President to protect such claims with military intervention, and establishes jurisdiction of criminal offenses under the laws of the United States within the territories, thus claimed. This encouraged American entrepreneurs to search for and exploit new deposits on tiny islands and reefs in the Caribbean and Pacific.
This was the beginning of the concept ofinsular area in U.S. territories. Up until this time, any territory acquired by the U.S. was considered to have become an integral part of the country unless changed bytreaty and eventually to have the opportunity to become a state of the Union. With insular areas, land could be held by the federal government without the prospect of it ever becoming a state in the Union.
On November 22, 1971, the United States handed over theSwan Islands toHonduras after signing theTreaty of the Swan Islands [es].[5] Honduras began exercising this sovereignty on September 1, 1972.[6]
Under the Act, the U.S. gained control of around 94 islands. By 1903, 66 of these islands were recognized as territories of the U.S.[7]
Whenever any citizen of the United States discovers a deposit of guano on any island, rock, or key, not within the lawful jurisdiction of any other Government, and not occupied by the citizens of any other Government, and takespeaceable possession thereof, and occupies the same, such island, rock, or key may, at the discretion of the president, be considered as appertaining to the United States.
— Section 1 of the Guano Islands Act
Section 6 provides that criminal acts on or adjacent to these territories "shall be deemed committed on the high seas, on board a merchant ship or vessel belonging to the United States; and shall be punished according to the laws of the United States relating to such ships or vessels and offenses on the high seas".[8] The provision was considered and ruled constitutional by the U.S. Supreme Court inJones v. United States,137 U.S.202 (1890).
The Act continues to be part of the law of the United States. The most recent Guano Islands Act claim was made in 1997 toNavassa Island. However, the claim was denied because an American court ruled the island was already under American jurisdiction (a claimHaiti disputes).[9][10]
While more than 100 islands have been claimed for the United States under the Guano Islands Act, all but ten have been withdrawn. The Act specifically allows the islands to be considered possessions of the U.S. The Act does not specify the territory's status after private U.S. interests abandon it or the guano is exhausted, creating neither obligation nor prohibition of retaining possession.
Current islands still claimed by the United States under the Act are:
A few islands claimed by the United States under theGuano Act of 1856 are disputed.
several islands first claimed under the guano island law; Kindle location 2856 of 15675.