In the early summer of 1919, Dwight Eisenhower was in a funk. With his wife and infant son living 1,500 miles away in Denver, the 28-year-old lieutenant colonel stationed at Maryland’s Camp Meade wasted away his considerable boredom by playing bridge with his fellow soldiers and drowning his sorrows about being kept stateside during World War I. Needing a way to break out of his doldrums, the future president found excitement in an endeavor still undertaken by millions today—the great American road trip.

Upon hearing that two volunteer tank officers from Camp Meade were needed to participate in a coast-to-coast military convoy to San Francisco, Eisenhower immediately volunteered his services. It may not have offered a young soldier the thrill of combat, but in 1919 a cross-country road trip was indeed, as Eisenhower described it, a “genuine adventure.”

“To those who have known only concrete and macadam highways of gentle grades and engineered curves, such a trip might seem humdrum,” Eisenhower wrote in “At Ease: Stories I Tell to Friends.” “In those days, we were not sure it could be accomplished at all. Nothing of the sort had ever been attempted.” At the dawn of the motor age, drivers were more apt to encounter roads to nowhere rather than the open road. Few highways were paved. Dirt roads could be muddy quagmires or sun-baked into teeth-chattering ruts. Sixty miles an hour remained a daredevil’s dream, and many roads could only be traversed at the pace of a brisk walk.

The War Department viewed the cross-country caravan—undertaken just months after the end of World War I—as part victory lap, part publicity stunt. Prodded by automakers, gasoline companies and tire manufacturers, the military saw the convoy as a way to both test the capabilities of the Army’s Motor Transport Corps and highlight the poor state of America’s roads.

Over the following days, unexpected detours arose when the roofs of covered bridges proved too low for the military’s shop trucks. The convoy halted repeatedly for stripped gears, boiled-over radiators and vehicles stuck up to their hubs in mud. The custom-design Militor tractor truck, which cost the military $40,000, quickly proved its considerable worth in towing vehicle after vehicle out of roadside ditches and mud holes with its power winch. One night the Militor even arrived in camp with four trucks in tow.

Band concerts, street dances, banquets and endless speechifying by local politicians greeted the two-mile-long convoy as it rolled across the country. Once the caravan crossed through Illinois it also left behind paved sections of the Lincoln Highway, the transcontinental road it had joined in Gettysburg, Pennsylvania. Scouts riding a fleet of Harley-Davidson and Indian motorcycles sped a half-hour in front of the convoy to inspect road conditions and blaze the trail ahead with painted arrows. In Nebraska, the trucks floundered in sand as slippery as ice. Outside North Platte, 25 trucks—including the Militor itself—slid into a roadside ditch. On one hellish stretch, it took the convoy seven hours to cross 200 yards of quicksand.

Two days were lost in Nebraska, but conditions grew even worse on Utah’s stretch of the Lincoln Highway, which Eisenhower reported was “one succession of dust, ruts, pits and holes.” Troops were forced to remove sand drifts from the road, and vehicles became stuck repeatedly in the desert where no rain had fallen for 18 weeks. When dozens of trucks mired themselves in the salt flats, the soldiers used their collective muscle to tow them out by hand. Like sun-beaten pioneers, the troops suffered from a lack of water, which was rationed to one cup for dinner and another for overnight. The commander even posted guards around the water tanker to prevent any pilfering until a shipment of water from the Utah Highway Commission arrived—being pulled by horses.

Once in California, the convoy returned to pavement and hit top speeds of 10 miles per hour. After being transported by ferry to the city’s docks, the vehicles paraded through the flag-festooned streets of San Francisco to the terminus of the Lincoln Highway six days behind schedule. The caravan had traversed 3,242 miles through 11 states in 62 days, an average of 52 miles per day.

The vehicles had performed well, given the conditions, but road conditions had proven wholly inadequate. “I think that every officer on the convoy had recommended in his report that efforts should be made to get our people interested in producing better roads,” wrote Eisenhower, who lamented the lack of investment in maintaining existing roads. “It seems evident that a very small amount of money spent at the proper time would have kept the road in good condition.”

As Supreme Commander of the Allied Forces in World War II, Eisenhower saw first-hand how Nazi Germany’s high-speed autobahn network allowed its troops to mobilize quickly to fight on two fronts. “After seeing the autobahns of modern Germany and knowing the asset those highways were to the Germans, I decided, as president, to put an emphasis on this kind of road building,” Eisenhower wrote. The 1919 trip, however, also remained in the forefront of his mind. “The old convoy had started me thinking about good, two-lane highways, but Germany had made me see the wisdom of broader ribbons across the land.” With America’s roads remaining in poor condition decades after his arduous cross-country trip, Eisenhower championed the creation of the American Interstate Highway System, which was officially named in his honor in 1990.