Burgers were invented in America.
Now sure, the Hamburger is named after Hamburg in Germany. However, the German version is actually the Hamburg steak. In other words, the meat patty. And a patty does not a burger make.
America was the country that put the bun on the hamburger. This, in drag’s opinion, is when the Hamburg steak became the “burger”. A new word, losing the ham and becoming what would be translated from German as “The people’s meal”. An apt description for the American burger.
Americans can say it’s American and Germans can say it’s German. Anybody else gets invaded.