Struggles over finite space are endemic to urban life, but in San Francisco the battles can be especially fierce. As a peninsular city, its geography alone limits its capacity to absorb newcomers, a constraint exacerbated by extensive regulatory obstacles to building new housing. Most recently, the influx of monied home buyers from Silicon Valley tech companies has transformed and gentrified entirely new areas of the city, such as the Mission District. The process has sparked more than a little tension as longstanding residents find themselves priced out.

More than a century ago, as an earlier battle played out between San Franciscans new and incumbent, the city’s Board of Supervisors took a very active role in deciding who San Francisco should be for. Their effort resulted in a bizarre but intriguing map designed to convey the grave and imminent “threat” posed to native San Franciscans by one emerging neighborhood in particular: Chinatown.

The Chinese were—like all Californians at the time—recent arrivals, attracted by the gold rush and the subsequent demand for labor to complete the Central Pacific Railroad. When the railroad was finished in 1869, many Chinese immigrants migrated to San Francisco, and by 1880 they constituted over 10 percent of the city’s population. Initially, Chinese residents and businesses had been dispersed throughout the city, but gradually they coalesced into a 15 square-block area of the city known then and now as “Chinatown.”

The Chinese influx came while the city was at the sharp end of a recession that had afflicted the entire nation. In this context, Chinese workers so desperately needed during the boom just a few years earlier became scapegoats for the economic crisis. The first anti-Chinese group formed in 1867, and by the 1870s this hostility was strong enough to sustain a new political party—the Workingmen’s Party—which set its sights on removing the Chinese “menace.” Attacks and anti-Chinese riots spread in the 1870s and 1880s.

It was a small step from blaming the Chinese for the city’s economic condition to blaming Chinatown for the city’s public health. Throughout the 1870s Chinatown was on watch, subject to routine surveillance and ongoing investigations. But San Francisco was not alone in such hostility: California’s virulent campaign against the Chinese ultimately resulted in the nation’s first restrictive immigration legislation in 1882. Ironically, however, the Chinese Exclusion Act made Chinatown even more attractive, as one of the few (relatively) safe havens against the persecution that Chinese immigrants experienced throughout the west.