Custom House
Monterey, Monterey County, California
Marker Inscription
Custom House Constructed in 1827 by the Mexican government to collect custom duties from foreign shipping, a principle revenue source when Monterey was the capital of Alta California, Mexico's northernmost province. Thomas O. Larkin, US consul to Alta California, contracted with the Mexican government in 1841 to rebuild and enlarge the Custom House. Commodore John Drake Sloat raised the American flag over this building on July 7, 1846 to signal the passing of California from Mexican to American rule. Restored through the efforts of the Native Sons of the Golden West with the assistance of the people of California. State Registered Historical Landmark No. 1 Registered June 1, 1932 National Historic Landmark designated 1960 Plaque placed by the Native Sons of the Golden West, the California State Parks Foundation, and California State Parks Rededicated 2014, the 150th anniversary of California State Parks
Erected by Native Sons of the Golden West
The Story
Built by the Mexican government in 1827, Monterey's Custom House collected duties on foreign shipping when the town was the capital of Alta California, Mexico's far northern province. U.S. consul Thomas O. Larkin contracted to enlarge it in 1841, and on July 7, 1846 Commodore John Drake Sloat raised the American flag over the building, signaling California's passage from Mexican to U.S. rule. Later restored, it stands today as California's first registered historical landmark.
Why it matters
This is where American California began, the customs post over which the U.S. flag first flew and Mexican Alta California gave way to the westward reach of the United States.
The story behind this marker
AI contextThe era
In the first decades of the 1800s, the stretch of Pacific coast we now call California was the far northern frontier of a young Mexico. Known as Alta California, it was Mexico's remote and sparsely settled northernmost province, and Monterey served as its capital — the administrative heart of a territory that felt a world away from Mexico City.
Life here revolved around the sea. Foreign ships arrived to trade, and the duties collected on their cargoes were among the most important sources of revenue the provincial government had. A port town that could tax incoming goods was a port town with real power, and Monterey's role as capital made its waterfront a place where commerce and government met.
This was also an era of shifting loyalties and rising outside interest. American, British, and other traders were drawn to California's harbors, and the United States was steadily expanding westward. The Custom House, built in 1827, stood at the very point where this frontier economy touched the wider world — and, in time, at the point where its political future would be decided.
People & events
The building's story runs through several hands. The Mexican government raised it in 1827 to collect customs duties, anchoring the fiscal life of the provincial capital. Then, in 1841, Thomas O. Larkin — the United States consul to Alta California — contracted with the Mexican government to rebuild and enlarge it. That an American consul was improving a Mexican customs house speaks volumes about how entangled the two nations' interests had already become on this coast.
The decisive moment came on July 7, 1846, when Commodore John Drake Sloat raised the American flag over this building. In that single act, the marker tells us, Monterey signaled the passing of California from Mexican to American rule. A customs house — a place built to count and tax the goods of a Mexican province — became the stage on which that province changed hands.
The honors that followed underscore how much the site came to mean. It was named California's State Registered Historical Landmark No. 1 in 1932, designated a National Historic Landmark in 1960, and restored through the efforts of the Native Sons of the Golden West with the help of the people of California, before being rededicated in 2014 on the 150th anniversary of California State Parks.
Its place in the American story
Few buildings can claim to mark the exact hinge point of a region's national identity, but this one can. When the flag went up over the Custom House in 1846, it was a public declaration that California was passing into the United States — one of the pivotal steps in the nation's dramatic mid-century expansion toward the Pacific.
The building's designation as California's Historical Landmark No. 1 is more than a bureaucratic footnote. Of all the sites the state might have honored first, this is the one it chose, an acknowledgment that American California, in a very real sense, began here. Its later elevation to National Historic Landmark status confirmed that the significance reaches beyond the state to the country as a whole.
There's a deeper resonance, too, in the fact that the story turns on a customs house. The transfer of California was about far more than a flag — it was about who would control this coast's trade, its harbors, and its future. A building devoted to commerce became the symbol of a continental shift in power.
If you visit
Come to the Custom House in Monterey and appreciate that you are standing before a building California itself singled out as its very first registered landmark. Look at the structure with that in mind: this is not a reconstruction of a famous event's location but the actual building over which the flag was raised, carefully restored so that later generations could stand where the moment happened.
Take in the setting near the historic waterfront and imagine the port as it once was — foreign ships arriving, cargo being tallied, duties collected for a distant capital. The building's very purpose as a customs house is part of the story, so let its plain, working character speak to you rather than looking for grandeur.
It anchors a walk through Monterey's deep and layered past, where the Mexican and early American chapters of California history sit close together. Read the plaque, note the span of dates it records — from 1827 to the rededications of our own time — and let this first-of-its-kind landmark set the tone for exploring the old capital around it.
Written by AI to add context, grounded in the marker’s inscription and the historical record. The inscription above is the original, unaltered text.
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Related people
- · Thomas O. Larkin
- · John Drake Sloat
Related events
- · Raising of the American flag at Monterey, July 7, 1846
Themes & tags
Nearby & related markers
Site of the Original Flagstaff, 1846
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