From Presidio to the Pecos River: Surveying the United States-Mexico Boundary along the Rio Grande, 1852 and 1853

The 1848 treaty of Guadalupe Hidalgo that ended the Mexican-American War described a boundary between the two countries that was to be ascertained by a joint boundary commission effort. The section of the boundary along the Rio Grande from Presidio to the mouth of the Pecos River was arguably the most challenging, and it was surveyed by two American parties, one led by civilian surveyor M. T. W. Chandler in 1852, and the second led by Lieutenant Nathaniel Michler in 1853.

Our understanding...