In March 1998, Cornerstone Construction & Materials, a subsidiary of Hanson plc acquired the H.G. Fenton Materials Co. In December 1998, Cornerstone added the acquisition of the Nelson Holding Company to the San Diego portfolio. Both H.G. Fenton and Nelson Holding Company were family-owned businesses in the San Diego market since the 1920s. The new additions made Cornerstone one of the largest producers of aggregates and ready mixed concrete in the area. Today, after a number of name changes, acquisitions and divestitures, Hanson Aggregates San Diego is part of Lehigh Hanson, Inc. The company and its employees have remained focused on providing the best products at the best value for their customers in the San Diego market.