Louis' Lunch is the New Haven restaurant widely credited with serving America’s first hamburger sandwich.
The restaurant traces its hamburger story to 1900, when a customer reportedly asked for a meal that could be eaten while walking. Owner Louis Lassen is said to have placed ground beef trimmings between toasted bread, creating the restaurant’s distinctive sandwich. Louis' Lunch continues to cook its beef patties vertically in cast-iron grills dating from the early twentieth century.
The claim is part of a broader hamburger-origin debate. Other restaurants and vendors, including establishments in Wisconsin and Texas, have their own evidence or traditions connected with the hamburger’s development. Consequently, Louis' Lunch is best described as widely credited rather than universally proven to be the sole inventor.
The restaurant’s modern burger is intentionally limited: it is served on toast with cheese, tomato, and onion, while ketchup is not offered. That unusual policy helps distinguish Louis' Lunch from standard fast-food hamburgers.