Classes were held in various places of the city, one in a 2nd floor room of Orbon's flour store, where Joseph Bowen, the founder and first teacher and principal, taught classes, and another in a one-room structure on Washington Square.
SJHS was located on Santa Clara Street and called the Horace Mann School, where the first diplomas were awarded to high school students.
In 1898, a new high school building was ready on Washington Square and declared at the time, one of the finest high schools in California. Early on Wednesday, April 18, 1906, the building was destroyed by the San Francisco earthquake.
After the earthquake, classes were held for two years in the Lincoln school building.
SJHS was housed on San Fernando Street, but with the growth of higher education, the state of California evicted the high school. The site is now San Jose State University.
SJHS is presently located at 24th and Julian Streets. Additional buildings were initially added through 1961 and recently have gone through renovations. The original building was selected by the Museum of Modern Art in New York City as one of the forty-three outstanding buildings of the postwar period.