Salisbury n.

place in Wiltshire, Middle English Salesbury, Old English Searobyrg, Searesbyrig, Roman Sorbiodoni, Sorvioduni. The first element is a British Celtic word of uncertain sense; the second is *dunon "a hill, fort" or else Gaulish *duro- "fort, walled town." The first element was altered in Old English by folk etymology and the second replaced by its native translation, burh.

Salisbury steak (1885) is named for J.H. Salisbury (1823-1905), U.S. physician and food specialist, who promoted it. 

In the Philadelphia Medical Reporter for January 10th, Dr. Hepburn describes the way in which the steak is prepared in the "Salisbury" treatment, which has acquired a great reputation in America for disordered digestion, and widely different diseases of a chronic kind, few drugs being employed simultaneously, and those chiefly of a tonic kind. The best slices of a round of beef are chopped off with dull knives, the object being rather to pound than to cut the meat. [from a report reprinted in several U.S. and British medical journals in 1885 that goes on to describe the method; this version from Homeopathic World, Aug. 1, 1885]

Incorrect use for "hamburger" generally traces to World War I and the deliberate attempt to purify American English of German loan words.