Hamburgers rarely contain ham because they are named for the German city of Hamburg, which had a historical reputation for producing quality beef.
Similarly, a frankfurter is named for the German city of Frankfurt.
The Salisbury Steak was named not for a city, but for 19th century physician James H. Salisbury. He promoted eating a lot of what he called “muscle pulp of beef,” especially for sick US Civil War soldiers, and suggested cooking it may be just as healthy as eating it raw, a common mid-1800s medical prescription for digestive problems. Notably, he was much less a supporter of fruits and vegetables. When his book was published in 1888, the mincemeat rage was one of the first American diet fads.