Kit has been in use as far back as the late 1200s and originally meant a round wooden tub, jug, tankard, or wooden container. Later it came to mean a knapsack as for a soldier, which contained all his needed items. Caboodle was first seen during the mid-1800s and from the earlier word boodle, meaning a collection of people among other meanings. Together they roughly mean all the people and all their things, the whole lot.
Kit and caboodle was first seen in print in 1884 in New York’s
Syracuse Sunday Standard: “More audiences have been disappointed
by him and by the whole kit-and-caboodle of his rivals.”