> During the decade between 1921 and 1931, the ports in Oakland and San Francisco both experienced explosive growth in commercial shipping, although the pace of

> During the decade between 1921 and 1931, the ports in Oakland and San Francisco both experienced explosive growth in commercial shipping, although the pace of growth favored Oakland. Prior to 1927 (when the Port of Oakland was formally organized), shipping tonnage in San Francisco more than doubled that in Oakland. By 1921 [sic] the gap had narrowed: Oakland handled about three-quarters the tonnage of San Francisco. Oakland's port would continue to outgrow San Francisco's through World War II before overwhelming it during the 1950s and 1960s. Source: A Tale of Two Bridges, p. 20, https://books.google.com/books?id=XiyVDwAAQBAJ&pg=PT20 https://books.google.com/books?id=XiyVDwAAQBAJ&pg=PT20