The influence of the United States military began as early as the events which led up to the Mexican-American War in the 1840s. In 1907, President Theodore Roosevelt sent the Great White Fleet on a worldwide tour as a show of economic and naval strength. World War I brought increased army and navy activity with the establishment of Camp Kearny and defense facilities at Fort Rosecrans and North Island. San Diego’s strategic position on the Pacific Coast gained greater attention with the creation of the Marine Base in 1919 and the Naval Training Station two years later.
Military presence in San Diego continued to grow as events in Europe and the Pacific indicated the probability of a second world war. The shock waves from the Japanese air strike on Pearl Harbor on December 7, 1941 had an immediate impact on San Diego — one which would have far-reaching consequences for the city. As San Diegans entered the war years, visions for the city were suspended in the united effort to win the war.