That same model is applied today in international banking. And his vision has been playing out on a national scale for the past 20 years. Fittingly, the first bank in the U.S. to have branches coast to coast is that same Bank of America, which accomplished the feat just this year through its $48 billion merger with NationsBank of Charlotte, N.C.

A.P. Giannini was born in San Jose, Calif., in 1870, the son of immigrants from Genoa, Italy. His father, a farmer, died in a fight over a dollar when A.P. was seven. His mother later married Lorenzo Scatena, a teamster who went into the produce business. Young A.P. left school at 14 to assist him, and by 19 he was a partner in a thriving enterprise, built largely on his reputation for integrity. At 31 he announced that he would sell his half-interest to his employees and retire, which he did. But then fate intervened, and his real career began.

At 32, A.P. was asked to join the board of the Columbus Savings & Loan Society, a modest bank in North Beach, the Italian section of town. Giannini soon found himself at odds with the other directors, who had little interest in extending loans to hardworking immigrants. In those days banks existed mainly to serve businessmen and the wealthy. Giannini tried to convince the board that it would be immensely profitable to lend to the working class, which he knew to be credit worthy.

He was soundly rebuffed. So in 1904 he raised $150,000 from his stepfather and 10 friends and opened the Bank of Italy--in a converted saloon directly across the street from the Columbus S&L. He kept the bartender on as an assistant teller. There he began to exploit his guiding principle: that there was money to made lending to the little guy. He promoted deposits and loans by ringing doorbells and buttonholing people on the street, painstakingly explaining what a bank does. Traditional bankers were aghast. It was considered unethical to solicit banking business.

Giannini also made a career out of lending to out-of-favor industries. He helped the California wine industry get started, then bankrolled Hollywood at a time when the movie industry was anything but proven. In 1923 he created a motion-picture loan division and helped Mary Pickford, Charlie Chaplin, Douglas Fairbanks and D.W. Griffith start United Artists. When Walt Disney ran $2 million over budget on Snow White, Giannini stepped in with a loan.