Where did the term "kit and kaboodle" come from?
It came from slang usage in New England USA
There are references to the whole caboodle dating from 1848
a caboodle is a group often of people but also a group of bundles.
Then in 1884 there are references to the whole kit and caboodle
The kit was used during the Civil War as a reference to the backpack sleeping mat and everything else the soldier would carrying with him on a military campaign. It is not clear if the caboodle is referring to the bunch of bundles that the soldier would carry along with his backpack or to a bunch of soldiers.
Then in 1888 the references to the whole kit and kaboodle are found. a boodle is only used in references to a bunch of bundles such as a bunch of straw. It is not clear if the change from caboodle or Kaboodle was for alliteration or to make clear the meaning between a bunch of bundles or a bunch of people.
The slang term from New England by the turn of the century was a reference to the entire kit ( backpack) and bundles (ka boodle) person might carry on a long trip. i.e. everything. A similar term in use today might be everything including the kitchen sink.