Actresses Dorothy Sebastian and Joan Crawford enjoy some hamburgers on a Los Angeles beach, c1925. (Credit: Getty)
Why are they called hamburgers?
From the grilled, minced beef patties that originated in the German city of Hamburg and that were introduced to America in the 19th century by German sailors or immigrants.
Where was the hamburger first commercially served in America?
Predictably, many places are keen to claim this honour.
The argument is complicated by disputes over what actually constitutes a hamburger.
For example, does it have to be in a bun?
New Haven, Connecticut enjoys the support of the Library of Congress in its claim that Louis Lassen (above) of local restaurant Louis’ Lunch first served chopped, pressed beef between two slices of bread in 1900.
On the other hand, Athens, Texas argues that Fletcher Davis had been serving them at his food outlet there since the 1880s and popularised them at the 1904 World Trade Fair at St Louis.