When did the Earl of Hamburg invent the hamburger?

The hamburger, as we know it today, was popularized in the United States in the early 20th century, but its origins can be traced back to the late 19th century. While the exact inventor is debated, it is often credited to various individuals, including German immigrants who brought the concept of a minced beef patty, similar to Hamburg steak, to America. The name "hamburger" is derived from Hamburg, Germany, but there is no specific "Earl of Hamburg" associated with its invention.