Potrero Point

The cut material was removed and used to fill two square miles into the San Francisco bay, making hundreds of acres of flat land.

Early factories were powder magazine plant, the Pacific Rolling Mill Company and small shipyards.

The large Union Iron Works and its shipyards were built at the site, stated in 1849 by Peter Donahue.

In 1854, DuPont built a black gunpowder factory at Potrero Point, at the current location of Maryland and Humboldt Streets.

Pacific Rolling Mills made products for the building, railroads and street cars in San Francisco.

Union Iron Works became a large shipyard and built US Navy destroyers for World War I.

The Transbay Tube, the Bay Area Rapid Transit's underwater tunnel, was built in segments at the site in the 1960s.

Carving the east side of Potrero Hill for a railroad line in 1870
Pier area c. 1918, looking north to Union Iron Works at Potrero Point
Claus Spreckels Suger Factory in Potrero Point in 1892