The morning of August 30, 1856 saw a force of several hundred Border Ruffians led by the pro-slavery leader John W. Reid entering into Osawatomie, in which Brown and his family were staying at the cabin of the Rev. Samuel Adair, the husband of Brown's half sister, Florella.
Having heard about his son's slaying, John Brown rushed from his camp toward Osawatomie, gathering several dozen men to meet the Missourian invaders.