1941
- Treasure Island is leased to the United States Navy, which opens Naval Station Treasure Island the next year
- World War II enlistment commences in the Bay Area (San Francisco recruiting office pictured)
- A two-masted schooner, Benicia, built in Tahiti by a shipwright who had worked in Matthew Turner's Benicia shipyard, arrives in San Francisco under the French flag
- The Xerces Blue butterfly is last observed in San Francisco either this year, or in 1943