The Columbia Steel Company opened a plant on the southern shore of Suisun Bay, east of San Francisco, in 1906. It was enough of an industrial hope for the small community that it changed its name from Black Diamond, to Pittsburg, in reference to the Pennsylvania steel town (but without the “h,” which was deemed unnecessary). The plant expanded through World War II, but then shrank again. Today it is a steel finishing plant, no longer making new steel, operated by U.S. Steel in partnership with South Korean company, POSCO.