Sutter's Fort was the first non-indigenous community in California's Central Valley. Fort Sutter was the seed that became Sacramento, and Sacramento and its gold rush paved the way for California. Basically, this small, modest fort is the birthplace of California.
Its founder, John Sutter, or at least his family name, is known widely in California. It's easy to find streets, parks, schools, and businesses with the Sutter family name. John Sutter was Swiss-German and later received Mexican citizenship but was never himself American, although he was a fan of at least one American pastime, slave labor.
John Sutter was neither a good businessman nor honest. He left Europe for the United States to escape his debts, and he left the United States for the Wild Wild West to escape his debts again. He fell into debt yet again and Fort Sutter was at risk until his son took over the business, which involved branching out and expanding the settlement into what is now Sacramento. John Sutter always resented his son for founding Sacramento.