San Francisco Bay was traversed by watercraft before the arrival of Europeans. Indigenous peoples used canoes to fish and clam along the shoreline. Sailing ships enabled transportation between the Bay and other parts of the world—and served as ferries and freighters within the Bay and between the Bay and inland ports, such as Sacramento and Stockton. These were gradually replaced by steam-powered vessels starting in the late 19th century. Several shipyards were established around the Bay, augmented during wartime. (e.g., the Kaiser Shipyards, Richmond Shipyards) near Richmond in 1940 for World War II for construction of mass-produced, assembly line Liberty and Victory cargo ships.