Attended by numerous federal dignitaries, and serving as the launch point for the Great White Fleet, the Jamestown Exposition also spurred interest in the military potential of the area. The site of the exposition would later become, in 1917, the location of the Norfolk Naval Station. The proximity to Washington, D.C., the moderate climate, and strategic location of a large harbor at the center of the Atlantic seaboard made Virginia a key location during World War I for new military installations. These included Fort Story, the Army Signal Corps station at Langley, Quantico Marine Base in Prince William County, Fort Belvoir in Fairfax County, Fort Lee near Petersburg and Fort Eustis, in Warwick County (now Newport News). At the same time, heavy shipping traffic made the area a target for U-boats, and a number of merchant vessels were attacked or sunk off the Virginia coast.