With the railroad's arrival in the late nineteenth century, immigrants of all colors rushed to the U.S.-Mexico borderlands, transforming the region into a booming international hub of economic and human activity. Following the stream of Mexican, Chinese, and African American migration, Julian Lim presents a fresh study of the multiracial intersections of the borderlands, where diverse peoples crossed multiple boundaries in search of new economic opportunities and social relations. However, as these migrants came together in ways that blurred and confounded elite expectations of racial order,...