Abstract: The use of height data to measure living standards is now a well-established method in economics and the social sciences. However, there are still some populations, places, and times for which anthropometric evidence remains thin. One example is 19th century Mexicans born in Mexico and in the American West. This paper demonstrates that the statures of 19th century Mexicans born in Mexico remained approximately constant, while the statures of Mexicans born in the U.S. increased by nearly 4cm, indicating that although the two groups shared a common genetic background, their cumulative biological living conditions differed markedly. The BMIs of Mexicans born in Mexico remained constant, and the BMIs of Mexicans born in the U.S. were high initially but rapidly converged in the late 19th century. [Copyright &y& Elsevier]