A little after 9:00 a.m. on April 19, 1995, a bomb made from a mixture of fertilizer and fuel oil destroyed the Alfred P. Murrah Federal Building in Oklahoma City, killing 167 people. Within days, agents of the Federal Bureau of Investigation (FBI) arrested Timothy McVeigh and Terry Nichols as suspects in the bombing, but law enforcement officials could only theorize about the two men’s motives. One possible motive was suggested by Morris Dees of the Southern Poverty Law Center (SPLC), which monitors the activities of right- wing and racist groups. The day after the bombing, Dees speculated that it was an act of retaliation for the FBI’s 1993 raid on the Branch Davidian compound in Waco, Texas. The raid—a fifty-one-day standoff ending on April 19, 1993— resulted in the fiery deaths of seventy-two members of the millenarian religious...