Documents with the signatures of U.S. presidents are appearing have historically appeared in some unexpected places: attics, libraries, or thrift stores.

Here’s an interesting mystery for you, though. An innocuous Civil War-era memo with Abraham Lincoln’s signature has been found in the state archives of Hawaii. Hawaii was not even part of the United States at that time! State researchers are attempting to solve this mystery.

The memo is dated September 22, 1862 and it orders the secretary of state to affix the U.S. seal to a separate piece of paper (a proclamation dated the same day). That proclamation was the Preliminary Emancipation Proclamation. Hawaii records indicate they’ve had the memo for at least 74 years. That’s some pretty impressive work by some long distance movers, I’d say.

Hawaii was overthrown by American residents in 1893, annexed to the United States in 1898, and became America’s 50th state in 1959.