biggest defeat in us military history
Size of force or number of deaths does not necessarily equate to worst - the question is not what was the largest defeat nor was it what was the defeat with the most casualties. As such, I would suggest that the worst defeat in US military history was the Battle of Little Big Horn, or Custer's Last Stand - a hastily decided attack by Custer left his troops ripe for the picking by the Soux and Apache warriors.