Cornwall, formerly known as Cornwall Station, was an unincorporated community in Contra Costa County, California, United States, before being absorbed into the City of Pittsburg. It was located east-southeast of Baypoint and south of downtown Pittsburg, at an elevation of ASL.

The area appears to have been named after Pierre Barlow Cornwall, an early California pioneer and president of the Black Diamond Coal Mining Company at nearby Nortonville from 1872 to 1904.Bruce Cornwall, "Life Sketch of Pierre Barlow Cornwall," (1906), pp. 60 and 82. Cornwall sprung up at the intersection of two railroads, the Black Diamond Coal Mining Railroad and the San Pablo and Tulare RailroadThe Pacific Tourist, J. R. Bowman, Publisher, 1882, p. 335. (the latter became part of the Southern Pacific system in 1888). The coal railroad crossed the San Pablo and Tulare line using an overhead trestle.

A post office operated at Cornwall Station from 1881 to 1888. Cornwall post office operated from 1890 to 1911.

The Cornwall area, together with the nearby town of Black Diamond, was officially renamed "Pittsburg" on February 11, 1911, which may explain why the Cornwall Post Office ceased operations in that same year.

References

External links Pierre Barlow Cornwall, 1821-1904 Life Sketch of Pierre Barlow Cornwall, written by his son Bruce Cornwall, 1906 Black Diamond Mines Regional Preserve, part of the East Bay Park District