"The killings in the church were indeed a terrorist act, part of the continuing terror of white violence that has threatened black men, women, and children ever since they were brought to the United States to be slaves. From the beginning, racism was a social construct to justify the enormous economic profit of turning children of God into chattel property. And that system of white supremacy has always used the practice and fear of violence against innocent black people to enforce itself. That's terrorism." Jim Wallis (full article).
Also worth reading: "America can't wash out the stain of slavery" - title of an article by Justin Webb - and:
"These shootings reveal an America still shackled to the ghosts of slavery" - title of an article by Amanda Freeman.