In a slightly nauseating yet informational video essay, Half as Interesting explains in great detail about the Guano Islands Act, an antiquated law that allows any citizen of United States to claim for their country, any random, unclaimed island containing deposits of bird excrement aka guano.
In the 1850s guano was selling in the US for as much as $75 per pound. That’s almost a third the cost of silver. People were making their fortunes by importing bird poop and the market in the US was dominated by only a few key players who spiked up prices. So William Henry Seward, the same guy who bought Alaska introduced a bill in the Senate which would allow any US citizen to claim any uninhabited island for the US as long as it had guano.