Its a good time to remember the 5,000 armed vigilantes who took over San Francisco in 1856

We live in a time of dizzying change.Our society is polarized by warring political and cultural beliefs.

Violence stalks our streets and even our schools.It feels like we are at the edge of a precipice. But we have been there before.One hundred and seventy years ago, San Francisco, the epicenter of today’s artificial-intelligence boom, was also spinning out of control.

Less than a decade before, massive amounts of gold had been discovered in the foothills of the Sierra Nevada mountains.Almost instantly what had once been a tiny trading post beside a quiet cove had become a booming city of 50,000.Twice a month a steamship departed for the East with a shipment of gold worth as much as $2 million (almost $80 million today).

Fast-sailing clipper ships, their holds stuffed with the luxuries of life, continually came and went through the appropriately named Golden Gate.“Money traveled fast and free,” a Californian remembered.

“People became intoxicated with prosperity.They overbuilt, overbought, threw money around in a reckless manner, and indulged to excess in all the harmful things of life.”And then, with no warning, the golden tide started to recede.

The supply of precious metals leveled off as new technologies such as hydraulic mining — industrial-scale firehoses capable of sweeping away entire hillsides — enriched a handful of corporations instead of thousands of individual miners.Many former prospectors turned to wheat farming, which reduced imports of grain.

Warehouses along the waterfront sat empty, and dockworkers lost their jobs.“The ripples of disaster spread wider and wider,” a San Franciscan remembered, “manifested by tenantless houses, declining wages and revenue.” The following year, banks started to fail.

The California Gold Rush had come to a screeching halt.In this terrifying new world of insecurity and doubt, a failed banker with the unusual name James King of William emerged as one of the San Francisco’s most widely read...