Before the Storm: Barry Goldwater and the Unmaking of the American Consensus by Rick Perlstein:
The country would have been lucky to get through the week. Governor Wallace was now standing in the doors of his state’s elementary and high schools. If integration went ahead, he said, he didn’t want any bloodshed—although if it happened, he said, civil rights agitators would be held responsible. Klansmen in Birmingham took the hint. The explosion inside the Sixteenth Street Baptist Church on September 15 was heard for two miles. Four little girls died in their Sunday school dresses. King wired Kennedy during the tensions that ensued: only the President’s intercession could prevent the “worst racial holocaust this nation has ever seen.” Ten days later another incendiary device exploded on Dynamite Hill, then a second, a shrapnel bomb intended to wound police if they investigated first. The Klansmen who were responsible copped pleas for misdemeanor possession of dynamite.