@Galactic Navy Officer The invention of the Hamburger is not clearly defined and can not be attributed to a single person as we have no clear evidence of its true origin. I agree with you that it has nothing to do with the city of Hamburg in Germany however the rest I do not agree with as the part about grond beef patties take off in the USA first has no evidence at all. Staying just with germany for example, you will find that they have what they call "Frikadelle" which is depending on how it is made either similar or equal to a meatball or a burger patty. Frikadelle dates back as far as the 17th century at the end of which we USA was just only been founded. Also we have to consider not the nation it was created in but the nationality of the creator in this case and the Hamburgers creation is attributed to a lot of people with room for discussion. It is a similar discussion to the origin of the "true" Hot Dog which to many was created in the USA and to be specific Coney Island .... by a German.
TL:DR
We have no conclusive evidence as to where the Hamburger originated and to be honest who cares so lets just give this manga the benefit of the doubt and go with Murica :P
TL:DR
We have no conclusive evidence as to where the Hamburger originated and to be honest who cares so lets just give this manga the benefit of the doubt and go with Murica :P