Although Hachi?ji only gained city status on September 1, 1917, it has been an important junction point and post-town along the K?sh? Highway, the main road that connected the historical Edo (today's Tokyo) with Western Japan since medieval times, especially during the Edo period. For a short period of time, a castle, Hachi?ji Castle existed in the area. It was built in 1584 by H?j? Ujiteru but was soon destroyed in 1590 during General Toyotomi Hideyoshi's attempt to gain control over all of Japan. During the Meiji period, Hachi?ji prospered as an important location for the production of silk and silk textiles. The industry faded away, however, in the 1960s. Today, Hachi?ji mainly serves as a commuter town for people working in Tokyo, and as a location for many large colleges and universities.
During World War II, captured American airmen were beheaded with samurai swords in Hachi?ji. When American pilots saw the published photos of the executions, they adopted the motto, "Save one for Hachioji", meaning hold back one bomb from their assigned bombing runs and drop it on Hachi?ji. The destruction was so extensive that, for decades after the war, American military personnel were warned not to visit Hachi?ji, because of the residual hostility to Americans.
During the 1964 Summer Olympics, the city played host to the road cycling events. A velodrome in the city played host to the track cycling events
