Giannini founded the Bank of Italy in 1904 to serve the Italian immigrant community of North Beach -- fishermen, farmers, and small merchants who were turned away by the established banks of the Financial District. He made small loans to people who had never had a bank account, built relationships based on personal trust rather than collateral, and expanded his customer base to include other immigrant communities. The Bank of Italy was a radical proposition: a financial institution that believed ordinary working people were good credit risks.

The 1906 earthquake and fire tested Giannini's philosophy and proved it correct. While other banks kept their vaults sealed for weeks (waiting for the safes to cool), Giannini lent money on handshakes to anyone who wanted to rebuild. He chartered ships to bring lumber from Oregon and Washington, personally guaranteeing the loans that allowed his customers to start construction. The people he lent to repaid their debts. The Bank of Italy grew rapidly, eventually becoming Bank of America in 1930. The Clay-Montgomery building where this transformation began still stands in the Financial District.

The Bank of Italy Building represents the starting point of one of the most remarkable institutional transformations in American financial history. A bank founded to serve Italian fishermen became the largest bank in the world, financing the Golden Gate Bridge, Hollywood studios, and eventually the growth of California's postwar suburban economy. Giannini's insight -- that small depositors and borrowers, served with respect, would build a more stable institution than large accounts alone -- proved revolutionary. The building on Clay and Montgomery is a monument to the idea that banking can be democratic.