At least four aerial fire trucks are at the scene battling the blaze, which has attracted a large crowd of onlookers.
As a result of the fire, Seventh Street has been closed for a copule blocks around the mill.
Dating to the mid-1800s, the 340-foot-long brick and heart pine structure, now closed, operated for a century as a flour mill along the banks of the Augusta Canal, according to a January 2007 article in The Augusta Chronicle.
The building on Twiggs Street, where James Brown played as a child and later filmed a music video, continued to decay, and was included among Historic Augusta's Top 10 list of endangered buildings. Last year, preservationists were hoping to get the ball rolling to save the building.