I just live near the area of the silver mine and am interested in the subject. Can anyone who knows a lot about the events during the US Civil War confirm/deny this article and give/point me to more information about California's role in the civil war? Anything specifically about the San francisco Bay Area's role in the civil war would be greatly appreciated. Thank you and have a productive day!
Just for clarification, "quicksilver" refers to mercury (which New Almaden produced). I have no comment on this assertion, but it is certainly overstated: California was a secure Union state.
The geological survey history of the mine published in 1964 seems to have some information on the topic.
At issue were land concessions granted by Mexico in territory that was ultimately acquired by the United States. For New Almaden - it involved mineral rights granted to one party - which extended for a certain distance from the mine itself - and how it overlapped on the actual concessions to two landowners. The owner of the original mineral rights was unable to get capital to develop the mine due to the start of the Mexican American war, and sold his rights to a British firm so he could cash out. The British firm was only able to get half of the land rights, and not the rights to the ground on which the mine actually stood.
The British firm started production, and had a good business going. But, the owners of the actual land ended up selling it to an American startup corporation based in New York. The American company challenged the British rights to the minerals - leading to the decision that the original grant was invalid. Hinted at in the source is the difficulty in reconciling common law and civil law regarding property ownership.
Whatever esoteric legal principles were played out (perhaps political ones as well) - the American firm won over the British firm - though the British firm already had the loyalties of the working population. And, any existing mining venture in the gold rush state would have to worry that their own claims might be challenged in the US court of law - so they opposed it.
By page 182 of that source the narrative reaches a head - but contrary to the article, it indicates that Lincoln remanded the order by stating that no wholesale seizure of mining properties was contemplated by the government. Perhaps they were just being nice to Lincoln? Either way, the issue was arbitrated by the Kaiser who ordered the Americans to pay the British some 1,750,000 dollars for their mineral rights. Seems to indicate that the issue really was as important as the article implies.
The technical details of the mining operation at the time were not much more advanced than those of the original Spanish proprietor. Those methods had been imported quite recently by priests from Spain - indicating that the Americans didn't have much of a native capacity for mercury. While important for gold production - a much more vital necessity was in play during these years in the form of mercury fulminate percussion caps. I might look to that as more of an incentive for Lincoln to act than precious metals.