Quantrill's Raiders were Confederate guerrillas who followed and fought under William Clark Quantrill.

Quantrill, an Ohio schoolteacher who relocated to Kansas, transformed himself into a militant murderer of abolitionists.

Some people view Quantrill and his men as avengers, paying back Union brutalities in kind. Others believe that they were cold-blooded killers. They targeted Union troops and civilian Union sympathizers alike.

Driven by their pro-slavery beliefs, they committed unprecedented atrocities—climaxing in the killing of 200 unarmed men and boys in Lawrence, Kansas, an event known as the Lawrence Massacre.