19th century, San Francisco's growing Chinese immigrants had to contend with codified prejudice from legislation like the 1882 Chinese Exclusion Act, segregated communities, and the sentiment that Chinese-Americans were the source of leprous, smallpox, and malarial "vapors." In 1900, a Chinese laborer was suspected of dying of Bubonic plague. Despite flimsy evidence of the disease, San Francisco city officials built a barbed wire partition around Chinatown.
"A rare photographic image of a nineteenth-century urban riot in progress. Sacramento Street east of Montgomery during the course of the disturbance, showing police lined up to thwart the intentions of those bent on destroying a "secesh" newspaper" - this is before Kye and Chance moved to SF, but it's too good a photo to pass up