Cornwall was an unincorporated community

Unincorporated area

In law, an unincorporated area is a region of land that is not a part of any municipality.To "incorporate" in this context means to form a municipal corporation, a city, town, or village with its own government. An unincorporated community is usually not subject to or taxed by a municipal government...

 in Contra Costa County

Contra Costa County, California

Contra Costa County is a primarily suburban county in the San Francisco Bay Area of the U.S. state of California. As of the 2010 census, it had a population of 1,049,025...

, California

California

California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, before it was absorbed into the City of Pittsburg

Pittsburg, California

Pittsburg is a city located in eastern Contra Costa County, California, the outer portion of the East Bay region of the San Francisco Bay Area. The population was 63,264 at the 2010 census....

. It was located 7.25 miles (11.7 km) east-southeast of Baypoint and 1 mile (1.6 km) south of downtown Pittsburg

Pittsburg, California

Pittsburg is a city located in eastern Contra Costa County, California, the outer portion of the East Bay region of the San Francisco Bay Area. The population was 63,264 at the 2010 census....

, at an elevation of 39 feet (12 m).

The area appears to have been named after Pierre Barlow Cornwall who was an early California pioneer and president of the Black Diamond Coal Mining Company at nearby Nortonville, California

Nortonville, California

Nortonville is a former settlement in Contra Costa County, California. It was located on Kirker Creek north-northeast of Mount Diablo, at an elevation of 801 feet ....

 from 1872 to 1904. Cornwall sprung up at the intersection of two railroads, the Black Diamond Coal Mining Railroad

Black Diamond Coal Mining Railroad

The Black Diamond Coal Mining Railroad was 5.9 miles long and ran from Black Diamond Landing, California to Nortonville, California. It was owned and operated by the Black Diamond Coal Mining Company and therefore did not have its own official name. Over the years, it has been known by at least...

 and the San Pablo and Tulare Railroad, (the latter became part of the Southern Pacific

Southern Pacific Railroad

The Southern Pacific Transportation Company , earlier Southern Pacific Railroad and Southern Pacific Company, and usually simply called the Southern Pacific or Espee, was an American railroad....

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 stopped operations in that same year.

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

External links

• Pierre Barlow Cornwall, 1821-1904
• Life Sketch of Pierre Barlow Cornwall, written by his son Bruce Cornwall, 1906