Diamond Shamrock

Company History: Diamond Shamrock Corp. or Diamond Shamrock Refining and Marketing was an oil refinery and gas station company in the United States, headquartered in San Antonio, Texas.

Since 2001, it operates as a brand of Valero and has withdrawn the brand from a majority of Texas gas stations and had converted most of the stores to Valero or sold them off to Texaco or other companies.

Brief History: The U.S. is a country of 50 states covering a vast swath of North America, with Alaska in the northwest and Hawaii extending the nation’s presence into the Pacific Ocean. Major Atlantic Coast cities are New York, a global finance and culture center, and capital Washington, DC. Midwestern metropolis Chicago is known for influential architecture and on the west coast, Los Angeles' Hollywood is famed for filmmaking.