At one time, the Custom House presided over Mexico's primary port of entry on the Alta California coast. It was here that Commodore John Drake Sloat raised the American flag in July 1846, claiming over 600,000 square miles of territory for the United States. This territory later was included in all or portions of the states of Utah, Colorado, Arizona, California and New Mexico.
This building is recognized as the oldest government building in California. It is State Historic Landmark #1.
Wander through this adobe building and find it as it looked in the 1840s. Try guessing to what purpose the items on display were used. Gaze out from the upper room where custom agents and soldiers once stayed. Watch for ships arriving from sea, much as the custom's officials did over 150 years ago.