By James Herlan

On June 17 the world was shocked by the brutal shooting of nine African-Americans who were attending a prayer meeting at their church in the U.S. city of Charleston, South Carolina.

Charged with the gruesome crime was Dylann Roof, an avowed white supremacist who has described African-Americans as “stupid and violent.”

Police arrested the 21-year-old within hours and he remains in custody, accused of multiple murders.

The depravity of the slayings has stunned Americans and puzzled citizens around the world, who find it difficult to comprehend.

Roof has implied the victims were killed because of the color of their skin, a viewpoint reflecting a rare degree of racism, even in the U.S. South where slavery had existed before the Civil War in the mid-19th century.

The causes of the gunman’s actions seem extremely complex and difficult to determine. Authorities will conduct psychological tests to assess Roof’s mental health when he shot the nine church members.

40% of the indentured Africans who came to America passed through Charleston.

But given the history of slavery and racism in the southern state and the city of Charleston, the influence of the past cannot be ignored as the public tries to come to grips with the crime.

Unique among British settlements in North America, South Carolina was founded as a slave colony. Charleston became a center of the slave trade, which prospered both before and after the American Revolution in the late 18th century.

The International African-American Museum (IAAM) in Charleston estimates that about 40% of the indentured Africans who came to America passed through the port city.

The trading of slaves was for years the heart of the city’s economy. From its founding, Charleston had an unusually high percentage of slaves in its population.

Just before the Civil War began in 1860, slaves made up half of the population of Charleston. According to the IAAM, the ratio of slaves to white settlers was once nine to one in the Lowcountry, a stretch near the Atlantic coast.

The existence of this economic manifestation of racism has had a lasting impact on the region.

As a strong proponent of slavery, South Carolina was one of seven states to form the Confederate States of America in March of 1861, effectively seceding from the United States. That triggered the Civil War, which broke out a month later with a Confederate attack on Fort Sumter in Charleston harbor.

Later, in 1868, South Carolina was readmitted to the United States. But even after the war ended, violent outbreaks against blacks continued, often generated by the racist Ku Klux Klan movement.

“Societies don’t, overnight, erase everything that happened 200 to 300 years prior.”

A climate of hatred in the state fostered a culture in which African-Americans could be mistreated. Although the civil rights movement of the 1960s helped improve conditions for minority citizens, the remnants of earlier eras never fully disappeared.

In the week after the slayings in Charleston, U.S. President Obama, speaking on the enduring power of racism, said, “Societies don’t, overnight, erase everything that happened 200 to 300 years prior.”

Many political leaders, including the governor of South Carolina, have started the process for removing the Confederate flag from the statehouse. Critics of the flag say it recalls the state’s previous defense of slavery and fans racism.

The governor’s supporters say that even if the flag is only a symbol, its removal would mark an important move away from past injustices.

The issue is complex since many citizens in the state view the flag as a positive symbol of their cultural past and a tribute to those who died serving in the Civil War. Many say they see no racist implications in the Confederate banner.

The debate in the South Carolina legislature will at least help clarify the meaning of the flag to both sides and could help reduce racial tensions in the region.