Obregon at El Paso - Glass negative photogrpah. Public domain.

Photograph shows General Alvaro Obregon, center, and his staff from left, Major Alberto G. Montano, Andres G. Garcia, the Mexican Consul in El Paso; Captain A. Gaxiola, and Colonel Aarón Sáenz Garza during the Juarez-El Paso conference, Ciudad Juarez, Chihuahua, Mexico, May 1916 during the Mexican Revolution. (Source: Flickr Commons project, 2014 and El Paso Herald, May 5, 1916)