Southco was started in 1970, having been originally located in Nashville, Tennessee under the name Southern Rolling Mills. Serving primarily as a warehouse for nails, the operation quickly outgrew itself and subsequently relocated to Wilmington, North Carolina. Since then, the company's product offerings were greatly expanded.

In 1988, with a change of ownership, the company changed its name to Southco Inc of North Carolina. Southco is now one of the largest independent distributors of steel pipe, reinforcing bar, mesh and other construction products in the Southeast.