u/CounterI

I assume that it would never happen and has never happened. But, apparently, the U.S. has given up land to another Country (Mexico) in modern history...

https://en.wikipedia.org/wiki/R%C3%ADo_Rico,_Tamaulipas

https://www.bbc.com/reel/video/p0f0tbmh/watch?utm_source=firefox-newtab-en-us