In 1860-61, eleven southern states seceded from the United States to protect the institution of slavery, forming the Confederate States of America and precipitating the Civil War. During the war, the Confederacy and its military forces used a variety of flags, but the flag that became most associated with the Confederacy was the so-called "battle flag." Organizations such as the Sons of Confederate Veterans adopted the flag as a symbol of Southern heritage but the flag also served as a potent symbol of slavery and white supremacy, which has caused it to be very popular among white supremacists in the 20th and 21st centuries. This popularity extends to white supremacists beyond the borders of the United States.
Today, the use of the Confederate flag is often controversial. While a number of non-extremists still use the flag as a symbol of Southern heritage or pride, there is growing recognition, especially outside the South, that the symbol is offensive to many Americans. However, because of the continued use of the flag by non-extremists, one should not automatically assume that display of the flag is racist or white supremacist in nature. The symbol should only be judged in context.