There are many reasons that brought Italians to California, but a couple of unique circumstances made California especially appealing. First, for northern Italians looking to emigrate from their homeland, California provided an established community for Ligurians in the San Francisco Bay. This was not the case on the eastern seaboard of the United States, which was dominated by southern Italians and Sicilians. The second reason for the exodus to California was the Oriental exclusion act of 1882, which created a need for agricultural workers that had not existed before. Those Italians that moved to southern California generally came from other immigrant enclaves. The 1900s saw the arrival of significant numbers of Sicilians to San Francisco, who came for the fishing harbors and the climate that resembled their old homes. These Sicilians still only made up 20% of the Italian immigrants to California, and were often segregated in housing and employment from those that had come earlier from northern Italy. The Sicilians were also kept out of the increasingly lucrative agricultural industries, as dairy became the domain of the Swiss-Italians, and wine was predominantly run by Ligurians.
It was during this period that Italian run and owned businesses became successful outside of the immigrant community. Amadeo Giannini founded what became the Bank of America in 1904 as a way for Italian immigrants to save and borrow small amounts, but the genius of his bank was the first use of branches put in locations closer to his customers. Ghirardelli's chocolates began gathering a following outside of the Italian community in San Francisco, and until Prohibition, Californian wines were acquiring a reputation as the best in the country.