The Settling and Seizure of California in the Polk Administration


Daniel Webster once remarked that the port of San Francisco was worth more to the United States than all of Texas. California was important in the functioning of the China trade and in the late 1830s, following the particularly severe Panic of 1837, many American pioneers made their way west, seeking new lives in the fertile regions along the Pacific coast. There were only 800 Americans in California in 1846. Following the establishment of the Bear Flag Republic and the discovery of gold at John Sutter’s mill, the American population soared to well over half a million. California was a crucial acquisition goal for the Polk administration.

Early European Claims to California

California was part of New Spain in the 16th Century, securing that claim through the establishment of numerous missions staffed by Franciscan priests and brothers. Small military garrisons were also housed on the mission compounds while a weak administrative staff represented Mexican interests in Monterey.

Upper California was also claimed by Imperial Russia as well as by Great Britain. The proliferation of Franciscan missions built after 1769 was designed to arrest further Russian expansion southward. British interests focused on the Oregon Territory, although claims to San Francisco were linked to Sir Francis Drake, whose circumnavigation in 1577-1580 involved an extended stay in the protected harbor.

Mexican Independence Changes the Role of Spanish Missions in California

In 1821 Mexico achieved independence from Spain and in 1833, under the leadership of Santa Anna, pursued a policy of secularization. The Franciscans had already been viewed unfavorably in Mexico City because of their opposition to the independence movement. Untrue stories of Native American abuse by the priests and brothers further damaged the missions.

The Mexican government ordered the missions to support the garrisons, promising financial compensation, but those reimbursements were never made. By the outbreak of the Mexican American War, all mission lands had been confiscated and Native Americans were resettled on land allotments. As would happen to tribes in America decades later, the system broke down and most of the land was acquired by white speculators.

American Pioneers Migrate to the Pacific Coast

California offered numerous fertile valleys that attracted settlers from the East, such as Sacramento in northern California. The Panic of 1837 increased migration in the westward movement, spurred on by newspaper stories and advertisements. This suited the U.S. government, especially the hyper-expansionists like John Tyler and James K. Polk.

Polk promised that, if elected, California, along with the other territories that came to be called the “Mexican Cession” in 1848, would be acquired by the U.S. By late 1845, explorer and adventurer John C. Fremont arrived on the Pacific coast.

After receiving a confidential letter from his father-in-law Missouri Senator Thomas Hart Benton, he led his small contingent of men south into California to help chart an independence movement. The result would be the proclaiming of the Bear Flag Republic.

California Becomes a Territory and State

Following the arrival of U.S. General Stephen Kearney in California and the defeat of Mexico, California became a U.S. territory. By 1849, the territory had written a free-soil state constitution and submitted it to President Zachary Taylor. This action reignited the fierce Congressional debate regarding the presence of slavery in the territories.

Polk had fulfilled his campaign pledge. President Taylor, who opposed the extension of slavery in the newly acquired territories despite being a planter himself, recommended California’s admission to the Union, accomplished in 1850 by yet another president, Millard Fillmore. The goals of Manifest Destiny had been met.


Frederick Merk, History of the Westward Movement (Alfred A. Knopf, 1978)
Frederick Merk, Manifest Destiny and Mission in American History (Vintage Books, 1966)
Page Smith, A Nation Comes of Age: A people’s History of the Ante-Bellum Years (McGraw-Hill Book Company, 1981)
John Edward Weems, To Conquer A Peace: The War Between the United States and Mexico (Doubleday, 1974)