In 1915 the United States was one of the few places in the world where high‑profile automobile racing continued at full throttle, even as World War I disrupted many sporting activities abroad. Major AAA (American Automobile Association) championship events drew top drivers and cutting‑edge machines. The Indianapolis 500, held on May 31 at the Indianapolis Motor Speedway, saw Italian‑born Ralph DePalma win in a Mercedes Grand Prix car, completing the 500 miles at a record average speed just under 90 mph in front of tens of thousands of fans. European‑built Peugeots and Mercedes vehicles, shipped before the war, added international flair to the otherwise mostly American field. The season also featured historic road races such as the American Grand Prize and Vanderbilt Cup, both run in February and March in San Francisco in conjunction with the Panama‑Pacific International Exposition, where British driver Dario Resta won both events in his Peugeot EX‑3. Across the board, oval board tracks and road courses hosted competitive fields, and European machinery influenced American innovation even as Europe’s motorsport world shifted toward wartime production.
In contrast, Europe’s organized Grand Prix racing largely ground to a halt in 1915 because of World War I. Before the war, events like the French Grand Prix had been among the most prestigious on the racing calendar; the 1914 French Grand Prix was a classic battle between French and German teams just weeks before conflict erupted. Once war began in mid‑1914, however, European automobile manufacturers and drivers were drawn into military service and factories switched from building racing cars to war materiel. As a result, formal Grand Prix series and most large road races were suspended for the duration of the conflict, with no major European championship races held in 1915.
The striking contrast between the two continents in 1915 highlights how American motorsport thrived in relative isolation while Europe’s rich racing culture was paused by global events. The absence of racing in Europe not only changed the competitive landscape but also contributed to technological cross‑pollination, as some advanced European cars and ideas found new life in the United States during this period.
