In March 1900 a Chinese immigrant was found dead in a San Francisco basement and a federal scientist confirmed bubonic plague, the first verified case on U.S. soil. What followed was a cover-up: the governor denied the plague for two years and branded the federal diagnosis fraudulent, and Chinatown was subjected to a discriminatory quarantine. Only after the governor lost office did Rupert Blue lead the first federal rat-eradication campaign.
Death toll figures are uncertain and likely undercounted given the cover-up. Historians debate how many lives the denial cost, and the racist quarantine was dressed as sanitation. The claim that the cover-up caused plague to become established in western rodents is plausible but unproven.