TIL America claimed dozens of islands purely for bird poop (1856) and is still an active law that allows any American to claim islands for guano. The most recent being 1997.

https://en.wikipedia.org/wiki/Guano_Islands_Act
#til #todayilearned
https://www.reddit.com/r/todayilearned/comments/1xfcmeo/til_america_claimed_dozens_of_islands_purely_for/