From the Guidebook:
The adobe-and-wood Larkin
House was built in 1835 by Thomas Oliver Larkin, a Yankee
merchant who came to California in April 1832. Since Larkin
was the only U.S. consul to California under Mexican rule,
his home became the American consulate from 1844 to 1846,
and it was also used as military headquarters by Kearny,
Mason, and Sherman.