In June 1846, Davis was one of thirty-three American insurgents who overtook the Mexican settlement of Sonoma, an act now known as the Bear Flag Revolt.

It was then that Davis and the remaining twenty-four men raised the Bear Flag, declaring an independent "Republic of California.

"[2] Jerome got his start in California as a ferry operator on the Sacramento River with his father-in-law, and later become a prominent landowner with 12,000 acres of farmland.

[3] 773 acres of his farm was purchased to be part of the newly formed University of California, Davis.

[1] Davis served as the president of the State Agricultural Society (predecessor to California Exposition), and opened the 8th annual California State Fair in 1861.