Louis Lassen, the founder linked to Louis’ Lunch’s hamburger claim, was Danish.
Lassen was born Ludvig Lassen on July 30, 1865, to a Danish family in Ballum parish in Schleswig. He immigrated to New Haven, Connecticut, from Denmark in 1881 and later operated a food wagon before opening Louis’ Lunch in 1895.
According to the Lassen family’s account, a hurried customer asked for a portable meal around 1900. Lassen used ground steak trimmings, grilled them, and served the patty between slices of toasted bread. Louis’ Lunch still presents this story as the origin of its hamburger sandwich, although the broader invention of the hamburger remains disputed.
A common mix-up is to call Lassen German because Schleswig was under Prussian control after the 1864 war and because “hamburger” refers to Hamburg, Germany. Those details concern geography and the dish’s name, not Lassen’s family background. The Library of Congress has recognized Louis’ Lunch’s claim, but other early hamburger claimants include Charlie Nagreen, the Menches brothers, Oscar Weber Bilby, and Fletcher Davis.