Yes. Just as the U.S. forces lost the Battle of Bataan and the Battle of Wake Island to the Japanese when they surrendered.
However, you originally used the term "losers" in the current insulting slang as in "a bunch of losers". Neither the Americans at Bataan or Wake Island nor the Japanese at Guadalcanl or Okinawa nor the Army of the Potomac at Chancellersville nor the Army of Nortern Virginia at Gettysburg were "losers" in the insulting context that you originally used that term by any stretch of the imagination.
BTW, what is your definition of "Loser"?
I would say that a "Loser" is someone like you who takes some sort of sick pleasure in going around insulting the ancestors of his fellow Americans.
Ok so I am a loser for pointing out that the rebel flag represents a bunch of losers. That's a real good one. yuk yuk.