You are right
but I saw the show on the History Channel and the phrase was first coined in WWII. This is from Wikipeda.
One of the most common explanations is that it dates from the Second World War, where "nine yards" was the length of an aircraft machine-gun ammunition belt, and to "go the full nine yards" was to use it up entirely. However, machine-gun ammunition belts were not nine yards long, and the expression has been reliably dated back only to early 1964, in U.S. Space Program slang. It was also apparently popular among Air Force personnel in Vietnam. By November 1967 it was recorded in use in the U.S. Army, likewise from Vietnam, and by mid-1969 was appearing in newspaper advertisements in the United States.