On October 24, 1871 anti-Chinese sentiments the small town of Los Angeles boiled over and resulted in the deaths of 19 Chinese by a mob of more than 500 whites.
The initial spark occured in Chinatown's, Calle de los Negros ("Negro Alley") near the Cornel Adobe by the city plaza. It was the result of two rival Chinese immigrant groups fighting over a young Chinese woman. However, when a mounted police officer attempted to end the argument, he was shot and killed. In less than 5 hours after the initial murder, an angry mob had formed and despite the attempts of Sheriff James F. Burns and Robert Widney, a well-known resident, to quell them,they murdered 19 Chinese victims, 15 of which were hung. Even the whites who attempted to protect the Chinese were attacked, one was killed.
In the aftermath, 7 of the more than 500 people involved were charged. However, only one was convicted and he wasn't even punished. It remains one of the worst outbreaks of racism in Los Angeles or the American West.
Pitt, Leonard/Dale. Los Angeles: A to Z