Casting Robert Vaughn
Steve McQueen and Robert Vaughn had previously co-starred in the 1960 movie, The Magnificent Seven.
Vaughn, who plays politician Walter Chalmers, didn’t like the script. He felt that there was neither a plot, nor a sensible story line.
McQueen insisted that Vaughn play it, but he continued to refuse–until the studio finally offered him a lot of money for the part.
After the experience, Vaughn said that his performance in this film was his best, containing the work he was most proud.
Several years later, Vaughn actively considered going into politics. To his dismay, he discovered that people couldn’t take him seriously, or found him untrustworthy, as they remembered his oily performance in this film.
Vaughn and Bill Hickman (who plays the Mafia driver) appeared together in Vaughan’s show The Man from U.N.C.L.E.: The Finny Foot Affair (1964).
McQueen, Vaughn, and Don Gordon appeared in The Towering Inferno (1974), a disaster adventure that was also set in San Francisco.