The Guano Islands Act

The Guano Islands Act (48 U.S.C. ch.8 §§ 1411-1419), passed in 1856, was federal legislation intended to ensure a steady supply of crap for America. The first section of this Act states,

"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 takes peaceable 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."

My guess is that Congress generates a sufficient quantity of guano these days for this law to be unnecessary.