Veterans of World War II have long sung the praises of the PX—a little piece of home in far-flung corners of the world. Though many books on that war tell of combat operations and logistics in detail, this is the first to tell the full story of the Army Exchange System.

The AES was dedicated to providing soldiers with some of the comforts they had enjoyed in civilian life—candy, beer, cigarettes, razor blades, soap—whether by operating an exchange close to where they were fighting or by sending goods forward to the lines, free of charge. The beer may have been only “3.2,” but it was cheap and, unlike British beer, was served cold, thanks to PX coolers. And a constant supply of cigarettes and chewing gum gave GIs an advantage when flirting with the local girls.

In chronicling the history of the AES, James J. Cooke harks back to the Civil War, in which sutlers sold basic items to the Yankee troops for exorbitant prices, and to the First World War, when morale-building provisions were brought in by agencies such as the Red Cross. He then traces the evolution of the PX through World War II from the point of view of those who ran the service and that of the soldiers who used it, blending administrative history with colorful anecdotes and interspersing letters from GIs.

Cooke views the PX as a manifestation of American mobility, materialism, and the cultural revolution of mass consumerism that flourished in the 1920s, serving soldiers who were themselves products of this new American way of retail and expected a high level of material support in time of war. He emphasizes the accomplishments of Major General Joseph W. Byron, chief PX officer from 1941 to 1943, and his deputy, Colonel Frank Kerr. He also tells how the PX dealt with the presence of large numbers of women in uniform and the need to meet their demands in exchange offerings.

By 1945, General Byron could boast that the Army Exchange Service operated the world’s largest department store chain, serving the grandest army the United States had ever put in the field, and today the PX is still a central factor of military life. Yet as Cooke shows, the key to the AES’s importance was ultimately the way it bolstered morale—and helped give our fighting men the will to keep fighting.

Although Juicy Fruit® gum was introduced to North Americans in 1893, Native Americans in Mesoamerica were chewing gum thousands of years earlier. And although in the last decade “biographies” have been devoted to salt, spices, chocolate, coffee, and other staples of modern life, until now there has never been a full history of chewing gum.

Chicle is a history in four acts, all of them focused on the sticky white substance that seeps from the sapodilla tree when its bark is cut. First, Jennifer Mathews recounts the story of chicle and its earliest-known adherents, the Maya and Aztecs. Second, with the assistance of botanist Gillian Schultz, Mathews examines the sapodilla tree itself, an extraordinarily hardy plant that is native only to Mesoamerica and the Caribbean. Third, Mathews presents the fascinating story of the chicle and chewing gum industry over the last hundred plus years, a tale (like so many twentieth-century tales) of greed, growth, and collapse. In closing, Mathews considers the plight of the chicleros, the “extractors” who often work by themselves tapping trees deep in the forests, and how they have emerged as icons of local pop culture—portrayed as fearless, hard-drinking brawlers, people to be respected as well as feared.

Before Dentyne® and Chiclets®, before bubble gum comic strips and the Doublemint® twins, there was gum, oozing from jungle trees like melting candle wax under the slash of a machete. Chicle tells us everything that happened next. It is a spellbinding story.