Book excerpt: David Torres-Rouff significantly expands borderlands history by examining the past and original urban infrastructure of one of America's most prominent cities; its social, spatial, and racial divides and boundaries; and how it came to be the Los Angeles we know today. It is a fascinating study of how an innovative intercultural community developed along racial lines, and how immigrants from the United States engineered a profound shift in civic ideals and the physical environment, creating a social and spatial rupture that endures to this day.