St. Patrick Mission Church was built during the heyday of grain exports and the arrival of the railroad that turned the tiny town of Port Costa, California into a major shipping hub in the late 1800s. Situated along the Carquinez Straits where the Sacramento River enters San Francisco Bay, ferries transported trains across the Strait to Port Costa where the trains would then continue on to the Port of Oakland. The construction of the railroad bridge across the Strait in the 1930s meant the town could be bypassed, taking with it most of its businesses and population. St. Patrick Mission Church was built in 1898 to handle the burgeoning population of the time. It never had a resident priest, with one crossing the Strait from Benicia to say Mass, or, as today, coming by land from the nearby town of Crockett to minister to Port Costa’s population of roughly 200 people.
From the slide archive.