Green’s Dictionary of Slang

(US) to drive an ox-team; thus bullwhacking n.

1869		A.K. McClure Three Thousand Miles through the Rocky Mountains 102: You will often find some graduate of Yale ‘bull-whacking’ his own team from the river to his mines, looking as if he had seldom seen soap and water.
1881		‘Bill Nye’ Bill Nye and Boomerang 34: Mule skinning, vocal music, horsemanship, plastering, bull whacking, etc., etc.