Mr. Thornton was the retired chairman of Southgate Corp., a trucking and warehousing business founded in Norfolk in 1892 and sold in 2003.
Mr. Thornton was elected to serve on the Norfolk City Council in 1965 and upon entering office in 1966 he spoke about the city's maritime potential: "I have said this before, but I repeat my conviction that maritime growth is the most important challenge facing Norfolk. The port offers the greatest potential for economic advancement and stability of any single facet of our area's existence."
In 1970, his family's long-time business interest in the maritime industry won him an appointment to the newly-constituted Virginia Port Authority. The VPA was established by then Gov. Linwood Holton in order to operate and market Virginia's major ports as a single port service.
In referring to the VPA board, Gov. Holton said, "It is my judgment that management and financial know-how are the keys to whether the ports can be brought together through negotiations."
Through significant and sustained investments from the state, the VPA moved to modernize the region's independently operated piers and to improve the area's channels in order for the newly unified ports to more effectively compete with other seaports along the east coast.
Thornton served as a VPA commissioner until 1982 overseeing the unification of the marine cargo terminals.
In 1952, Mr. Thornton joined his father at Southgate Corp. as an assistant manager for the company's trucking division. Southgate operated principally in the warehousing, trucking and distribution business. The company concentrated mainly in the distribution of import and export shipments arriving from and departing through the area's marine and rail terminals.
In 1974, Mr. Thornton became president of the company and a few years later he was successful in purchasing 12 acres in the Norfolk Industrial Park for new corporate offices and a distribution facility. He became chairman in 1990 and retired from the business in 1992.
Mr. Thornton earned his undergraduate degree in civil engineering in 1943 from Virginia Military Institute.
Upon graduation he joined the Marine Corps and was commissioned a lieutenant. He fought with the 6th Marine Division which took part in the assault on and capture of Okinawa and was awarded the Bronze Star Medal (with V) while serving as a platoon leader in the 6th Engineer Battalion. In addition, he witnessed the surrender of the Japanese forces in this area of China on Oct. 25, 1945.
He was recalled to active duty with the 2nd Marine Division from 1950 – 52 as a captain.