By Paul J. Vanderwood and Frank N. Samponaro; University of New Mexico Press; 312 pages.

Of all the modern mediums of written communication, the postcard is probably the most sentimental and lighthearted. But as this handsome volume of picture postcards depicting the Mexican Revolution of 1910 and the war between American troops and Mexican rebels demonstrates, postcards once served a very different function. They were, in fact, a form of primitive news bulletin. Professional photographers, and even more often amateurs, would rush to the scene of flash floods, fires, tornadoes, strikes, and other newsworthy events and then put their photos on postcards for general distribution. These cards acquired an enormous circulation.

The postcard was introduced into the United States on May 1, 1873, when the Post Office Department began to issue postal cards to postmasters throughout the nation. Within six months Americans had bought sixty million of the cards. In the 187Os publishers began to print holiday greetings and advertisements on postcards. It was not, however, until 1893 at the World’s Columbian Exposition in Chicago that picture postcards came into general use as souvenirs of an unusual spot or sight. In 1907 the popularity of postcards surged when postal legislation allowed divided backs on postcards. Now the sender of a card could write a short message on the back. The popularity of postcards profoundly transformed the writing habits of Americans, who came to rely less and less on long letters.

One of the first major events to receive attention from postcard publishers was the Mexican Revolution and the ensuing struggle between American troops and rebel guerrillas. Americans learned the course of the rebellion through the thousands of postcards they purchased. An astonishing variety of cards churned out by local amateur photographers as well as by larger, more profitable firms brought home the first skirmishes between U.S. and rebel troops at Agua Prieta, Sonora, in 1911, the April 1914 landing of American sailors and Marines at Veracruz, and the March 1916 expedition of American troops into the interior of Mexican territory led by Gen. John J. Pershing.

The postcards not only offered an exciting sense of the progress of the war—the battles, the skirmishes, the defeats, and the victories of a long struggle—but also provided a series of arresting images that conveyed a sense of the varied experience of life during wartime: the hardship visited on the troops by the Mexican heat and dust, the boredom and tediousness of army life, the long bouts of waiting for transportation or supplies, the extended periods of inaction, as well as the camaraderie and playfulness in the barracks. The most serious and important contribution that these postcards make to the historical record can be found in the wealth of period detail they contain—precise information unavailable elsewhere concerning troop movements, battle tactics, morale, weapon types, and the personalities of generals, rebels, and politicians.