Mexico at the Hour of Combat: Sabino Osuna’s Photographs of the Mexican Revolution is both a new book as well as a travelling exhibition based on the Sabino Osuna Collection of 427 glass negatives of the Mexican Revolution, held at the Special Collections section of the University of California, Riverside. The collection mainly covers the period 1910 to 1914 although little is known about the principal photographer, Sabino Osuna. Evidence suggests that he was a commercial photographer in Mexico City, whose work shifted from portraiture and architectural studies to photo history when the Revolution began. The book, edited by Ronald Chilcote (Professor Emeritus in Economics at UC Riverside) and published by Laguna Wilderness Press, provides striking images of the Mexican Revolution that are unique and largely unknown.