Tanforan Racetrack was built on the San Francisco Peninsula in San Bruno, constructed to serve a wealthy clientele from the city. Horse racing in the Bay Area at the turn of the century was a high-stakes business tangled with political power, gambling interests, and the social ambitions of California's nouveau riche. The track attracted top thoroughbreds and drew crowds from across the region. In its early decades, Tanforan competed with other Bay Area tracks for the attention of bettors and the favor of racing commissions. The facility also hosted early aviation exhibitions, part of the national craze for flight demonstrations that followed the Wright Brothers' breakthrough.

In April 1942, the racetrack was seized by the Wartime Civil Control Administration and converted into the Tanforan Assembly Center under Executive Order 9066. Nearly 8,000 Japanese Americans, most of them United States citizens, were confined here while permanent internment camps were built in the interior. Families lived in converted horse stalls. The detention lasted about six months before detainees were transferred to the Topaz War Relocation Center in Utah. The use of a racetrack -- a place built for entertainment -- as a prison camp for American citizens gives Tanforan its particular historical weight. The horse stalls designed for animals were repurposed for people, a physical fact that requires no metaphorical elaboration.

After the war, Tanforan returned to horse racing from 1947 to 1963. When racing ended, the site was redeveloped as The Shops at Tanforan, a shopping mall that operated from 1971 to 2022. The San Bruno BART station, which opened adjacent to the site in 2003, now hosts a permanent memorial to the assembly center with photographs and a bronze statue. The layers of use -- track, prison, mall, transit hub -- create a palimpsest that is uniquely Californian. Each era overwrote the last without fully erasing it. A memorial plaza dedicated in 2022, with a reconstructed horse stall, ensures that the darkest layer remains visible.