Why are hamburgers called hamburgers when they are made from beef and not ham?

According to the Food Lovers Companion, The name "hamburger" comes from the seaport town of Hamburg, Germany, where it is thought that 19th-century sailors brought back the idea of raw shredded beef (known today as beef tartare) after trading with the Baltic provinces of Russia

The common belief is that the American hamburger borrowed its name from a dish called "Hamburg Style Beef" or "Hamburg Steak" which arrived in the United States from the German city of Hamburg in the 19th century. The dish was nothing more than chopped meat eaten raw