Douglas Harper's Etymology Dictionary
by 1970, of unknown origin; perhaps arbitrary (see cloud nine). Among the guesses that have been made without real evidence: concrete mixer trucks were said to have dispensed in this amount. Or the yard might be the word used in the slang sense of "one hundred dollars." Several similar phrases meaning "everything" arose in the 1940s (whole ball of wax, which is likewise of obscure origin, whole schmear); older examples include whole hog (see hog (n.)) and whole shooting match (1896); whole shebang (1895).
Usage examples of "whole nine yards".
You know, Sergeant Rock, the howling commandos, the whole nine yards.
If you want to do another Song Tay, you can duplicate the whole plan, crash the chopper in the compound, the whole nine yards - but I keep hearing you want it done small.
I'd always been into guns-hunting, the outdoors, the whole nine yards.
Learned the old prayers, studied the rituals, the whole nine yards.
Not just itty-bitty things, either, but monsters with pools and party decks, the whole nine yards.
Lunk was in for the whole nine yards, as the ancients put it, to Reflex Point.
Ikea--you name it, track lights, entertainment center, the whole nine yards.
I told him Skip was still under the weather, suffering from exhaustion, the whole nine yards.