All Over the Map: “Upper California” in 1846

by Paul R. Spitzzeri

One hundred and seventy years ago, the United States was deep in its first imperial war, a conflict with Mexico that was, by any standard, launched on a pretext of conquest.  President James Polk and his allies and supporters were determined to seize as much of the territory of Mexico between the recently annexed Texas and the Pacific Ocean as possible.

The war came to California in the summer of 1846 and was over within several months.  Locally, the first seizure of Los Angeles took place rather quickly, though Californios quickly resisted and took back control of the town and surrounding areas.  In early 1847, however, another American force marched from the south and, after engaging in battle with locals on 9 January, retook Los Angeles and effectively ended the conflict in California.


As will be discussed further in future posts, William Workman had a role in local wartime events, helping to free Americans and Europeans seized prisoner by Californios at the Battle of Chino in modern-day Chino Hills, serving as negotiator with Commodore Robert F. Stockton on the latter’s march towards Los Angeles in early January, and bringing out the flag of truce when the conflict ended.  Later, he housed returning former governor Pío Pico and incurred the wrath of the Los Angeles garrison commander for doing so.

While the war was on in 1846, prominent American map-maker Samuel Augustus Mitchell published some hand-colored maps showing the presumed size of what he called “Upper California” or “New California.”  Appearing in a later edition of his Mitchell’s School and Family Geography, there are two maps from the Homestead’s collection that show the territory then in the midst of conquest.


Map #4 is of the North American region from “Russian America” (Alaska, purchased by the United States twenty years later), “British America” (Canada), and Greenland, south to Central America and the West Indies.  A substantial area in pink at the center left portion shows “Upper California.”

Going to a detailed close-up view, what is striking is how Mitchell defined the California region.  While the northern boundary is along the current line separating California from Oregon, note how far east the line runs into what became Wyoming and Colorado.  South from there the eastern boundary moves through Utah, Colorado and New Mexico, coming very near the principal towns of the latter, like Santa Fe and Albuquerque.  Also notable is the southern boundary, a curved line much further south than today’s international line between the U.S. and Mexico.


Because the map is very broad and generalized, only a few place names in California are identified, such as San Diego, San Luis [Obispo], Monterey,  San Francisco Bay, also called “Bay of Sir Francis Drake,” the 17th century British explorer, and Cape Mendocino.

More detail is provided in map #15, titled “Map of Oregon and Upper California.”  Including “British America” in what is now British Columbia and a sliver of the Missouri Territory in Idaho, the map shows a larger Oregon area including what became the state of Washington.

Otherwise, the area defined as “Upper or New California” is the same as in the other map, though there are more place names.  These include rivers, lakes, passes, coastal points and capes, a couple of the Channel Islands, as well as towns.  The reason we know this map comes from a later edition of the 1846 version is because of the listing of the “gold regions” and the use of the name “San Francisco” for what had been, in 1846, the tiny hamlet of “Yerba Buena.”  Meantime, the “Pueblo de los Angelos” and the mission town of San Juan [Capistrano] are the identified place names in greater Los Angeles.


Clearly these maps expressed the opinions and hopes of many about what California might be once the war with Mexico ended and a treaty ratified determining what territory was to go to the U.S. Obviously, when the Treaty of Guadalupe Hidalgo was ratified on 2 February 1848, the process began within the American political system about what to do with its massive new acquisitions.

When boundaries were laid out, California became, of course, far smaller, than what this map showed.  For one thing, the Mormons found their Zion at the Great Salt Lake and the creation of the Utah Territory ensued including what on the map was optimistically called “The Great Interior Basin of California.”  Moreover, the New Mexico Territory was extended generally to the Colorado River.

As a cartographic snapshot of a vast area of North America still in the midst of a war and soon to be subject ot a great deal of political haggling and negotiation, these maps are fascinating documents.  Check back here for more installments of “All Over the Map” to see what other great maps the Homestead’s collection contains.

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