William S. O'Brien

William Shoney O'Brien
File:William S. O'Brien.jpg
Born	c. 1825 Abbeyleix, Ireland
Died	Template:Dda San Rafael, California
Resting place	Holy Cross Cemetery, Colma (reinterred from San Francisco's Calvary Cemetery)
Nationality	American
Occupation(s)	Saloonkeeper, stockbroker, partner in Comstock Lode mines
Organization(s)	Flood & O'Brien Consolidated Virginia Mining Company Bank of Nevada
Known for	Being one of the "Bonanza Kings"

William Shoney O'Brien (circa 1825 – May 2, 1878) was an Irish-born entrepreneur who teamed up with fellow Irish immigrants James Graham Fair, James C. Flood, and John William Mackay in the Consolidated Virginia Mining Company. Their group managed silver mining operations on the Comstock Lode and uncovered the "Big Bonanza" in 1873—a valuable ore deposit extending over 1,200 feet deep that initially yielded as much as $632 per ton and amassed nearly $190 million by 1877. This partnership, commonly referred to as the Bonanza firm, was officially named "Flood and O'Brien."

Early life

O'Brien was born around 1825 in Abbeyleix, Ireland, which was then part of Queen's County (now known as County Laois).

Career

After relocating to the United States and establishing himself in San Francisco, California, O'Brien joined forces with James C. Flood to open the Auction Lunch Saloon on Washington Street in 1857. By 1868, having built considerable wealth, they sold their saloon business and started a brokerage firm. There they encountered James G. Fair and John W. Mackay, forming a partnership with combined capital of $225,000 aimed at wresting control of the Hale & Norcross silver mine in Virginia City, Nevada from William Chapman Ralston. In 1869, they acquired a controlling interest in the mine’s stock, ousting Ralston and boosting production threefold that year and fourfold by 1870.

Their discovery of the Consolidated Virginia silver lode ("Big Bonanza") in 1873 earned them reputations as the Silver Kings and Lords of the Comstock. Additionally, they established the Nevada Bank in San Francisco in 1875 with Louis McLane as its inaugural president. The institution was renamed Nevada National Bank in 1898 before merging with Wells Fargo Bank in 1905.

Noel M. Loomis characterized O’Brien as modest and unpretentious yet well-regarded among his Silver King partners. Remaining unmarried at his passing in 1878, he left behind an estate valued at $15 million.

Personal life

Ranked among the top 100 wealthiest individuals in America at the time, O’Brien accumulated substantial riches throughout his career. He passed away from Bright’s disease on May 2, 1878, in San Rafael, California.

Initially interred at Calvary Cemetery in San Francisco, his remains were later relocated to Holy Cross Cemetery in Colma following Calvary’s closure. Architectural plans for O’Brien’s monument at Calvary Cemetery are preserved within U.C. Berkeley’s Bancroft Library archives.