The annexation of Texas to the United States in 1845 and the conquest of what became the American Southwest in the Mexican-American War of 1846–1848 reduced the size of Mexico by more than half and increased the size of the United States by a third. These acquisitions also reopened the vexed question of slavery’s expansion, which supposedly had been settled by the Missouri Compromise of 1820.

Three months into the Mexican War, Pennsylvania Congressman David Wilmot introduced his famous “Proviso” stipulating that in any territory acquired from Mexico “neither slavery nor involuntary servitude shall ever exist in any part of said territory.”1 Almost unanimous support by Northern congressmen, Whig and Democrat alike, passed this resolution over the virtually unanimous opposition of representatives of both parties from the South. In the Senate, however, the equal representation of the fifteen slave states and fifteen free states enabled Southern senators to block Wilmot’s Proviso.

These events sounded an ominous knell for the future of the republic. Congressional votes normally divided along party lines, with Northern and Southern Democrats lining up together against Northern and Southern Whigs. The wrenching of this partisan pattern into a sectional split on the Wilmot Proviso foreshadowed the increasing polarization that finally plunged the nation into disunion and civil war fifteen years later.

It was all so unnecessary, according to historians whose interpretation of the Civil War’s causes once prevailed. With the expansion of the cotton frontier into eastern Texas in the 1830s, they maintained, slavery had reached the “natural limits” of its growth and could spread no farther into the arid and inhospitable Southwest.2 This Natural Limits thesis sustained an argument that the Civil War was a needless war, a “repressible conflict” brought on by self-serving Northern politicians who seized on the artificial issue of slavery’s expansion to vault into power by scaring Northern voters with false alarms about an aggressive “Slave Power.” Their self-righteous anti-Southern rhetoric finally goaded slave states into secession when Abraham Lincoln won the presidency in 1860.3

The Natural Limits thesis echoes the voices of antebellum politicians exasperated by antislavery claims that slaveholders intended to expand their “peculiar institution” into the territory taken from Mexico. This whole matter, insisted one Southern congressman, “related to an imaginary negro in an impossible place.”4 President James K. Polk, who presided over the Mexican War, wrote in his diary that the agitation about slavery’s expansion was “not only mischievous but wicked” because “there is no probability that any territory will ever be acquired from Mexico in which slavery could ever exist.”5 Senator Daniel Webster insisted that the arid climate would keep slavery out of these territories, so why insult the South by the Wilmot Proviso legislating exclusion? “I would not take pains to reaffirm an ordinance of nature,” said Webster, “nor to reenact the will of God.”6 Kentucky Governor John J. Crittenden maintained in 1848 that “the right to carry slaves to New Mexico or California is no very great matter…and the more especially when it seems to be agreed that no sensible man would carry his slaves there if he could.”7

It comes as something of a surprise, therefore, to discover that the territories of Utah and New Mexico (which also included the future states of Nevada and Arizona) legalized slavery in 1852 and 1859 respectively, that slaveholding settlers in California made strenuous and partly successful efforts to infiltrate bondage into that state, and that California’s representatives and senators voted mainly with the proslavery South in the 1850s. The distinguished historian Leonard L. Richards was born and raised in California, but learned nothing of this history from his teachers and textbooks there. “Somehow I had gone through the California schools from kindergarten through graduate school,” he writes, and never heard or read that several of the state’s early political leaders “might as well have been representing Mississippi or Alabama in national affairs.” One reason for writing The California Gold Rush and the Coming of the Civil War, he explains, was “to bring myself up to speed—to learn material that I should have learned forty or fifty years ago.”

About the same time in early 1848 that the Treaty of Guadalupe Hidalgo transferred California from Mexico to the United States, workers building a sawmill on the American River near Sacramento discovered flecks of gold in the riverbed. Word of this find leaked out despite efforts to keep it secret. Rumors reached the eastern United States in August 1848, where a public surfeited with tall tales out of the West initially proved skeptical. Lieutenant William Tecumseh Sherman, aide to the military governor of California, persuaded his commander to send a tea caddy containing more than two hundred ounces of pure gold to Washington. It arrived in December 1848, two days after President Polk confirmed the “extraordinary” discoveries of gold. All doubts vanished. By the spring of 1849 tens of thousands of men from all over the United States as well as Chile, China, Mexico, Australia, France, and other countries were on their way to California. So many arrived that by the fall of 1849 the region had as large a population as Delaware and Florida, which were already states.


These men (and they were nearly all men) in San Francisco and the mining camps needed law and order, courts, land and water laws, mail service, and other institutions of government. The national House of Representatives with its Northern majority passed legislation to organize California as a free territory. Southern strength in the Senate blocked this move. Settlers in California soon took matters into their own hands. In October 1849 they drew up a state constitution and petitioned Congress for admission. The Whig administration of President Zachary Taylor (elected in 1848) supported statehood as a way of circumventing the troublesome issue of slavery in California as a territory.

The problem was that the proposed state constitution (modeled on Iowa’s) banned slavery. Most of the Forty-Niners wanted to keep that institution out of California not because of moral principle but because they did not want to compete with slave labor. Several slave owners had in fact brought their bondsmen with them to work in the mines. “There is no vocation in the world in which slavery can be more useful and profitable than in mining,” declared one of the South’s leading newspapers, The Charleston Mercury. Another paper, The Southern Quarterly, declared that “California is by nature peculiarly a slaveholding State.” If it were not for the agitation to exclude slavery, “thousands of young, intelligent, active men…would have been in that region, having each carried with them from one to five slaves.”8

Senator Jefferson Davis of Mississippi pointed out that “it was to work the gold mines on this continent that the Spaniards first brought Africans to the country.” Although Davis had never been to California, he insisted that “the European races now engaged in working the mines of California sink under the burning heat and sudden changes of the climate, to which the African race are altogether better adapted.” Davis denounced California’s free-state constitution as having been written by “a few adventurers uniting with a herd as various in color and nearly as ignorant of our government, as Jacob’s cattle.”

Underlying this rhetoric was the Southern fear that admission of California as the sixteenth free state would tip the balance of power against slave states in the Senate and set a precedent for additional free states from the Mexican cession. “For the first time,” warned Davis, “we are about permanently to destroy the balance of power between the sections.” This was nothing less than a “plan of concealing the Wilmot Proviso under a so-called state constitution.”9 The exclusion of slavery from California was described as an unconstitutional violation of Southern property rights and political equity that would justify a drastic response. “If by your legislation you seek to drive us from the territories of California and New Mexico,” thundered Representative Robert Toombs of Georgia, a rich slaveholder, “I am for disunion.”

Several Southerners echoed Toombs’s threat. Secession and perhaps war in 1850 over the admission of California seemed a real possibility. Into this crisis strode the venerable Senator Henry Clay with a compromise proposal, as he had done twice before in 1820 and 1833. Clay’s compromise would offset the admission of California as a free state and the abolition of slave trading in the District of Columbia (an international embarrassment) by the admission of New Mexico and Utah without restrictions on slavery, by a guarantee of slavery itself in the District of Columbia against federal interference, and by a powerful new fugitive slave law to be enforced by federal marshals, commissioners, and if necessary the army to return slaves who had escaped to free states. One by one these measures became law during a long and contentious session of Congress in 1850. Many Southerners continued to protest the admission of California, but just enough of them voted for it (or abstained) to get it through Congress. And just enough Northerners in return supported the quid pro quo measures favoring the South.

The fears expressed by Jefferson Davis and others that California would tip the balance against the South in Congress proved baseless. The state could scarcely have given the South more aid and comfort in national politics if it had been a slave state. The Democratic Party dominated California politics through the 1850s. And that party in turn was dominated by a coalition of Southern-born politicians that became known as the “Chivalry.” Most of them continued to own slaves in the states from which they had emigrated. The foremost “Chiv” was William Gwin, a Mississippi planter who arrived in California in 1849 and served as one of its senators for most of the next decade. Gwin controlled federal patronage in the state during the Democratic administrations of Presidents Franklin Pierce and James Buchanan. The other California senator from 1851 to 1857 was, in the political lexicon of the time, a “doughface”—a Northern man with Southern principles. Together these senators voted for every proslavery measure demanded by Southern Democrats, most notably the Kansas-Nebraska Act of 1854, which repealed the earlier ban on slavery in Louisiana Purchase territory north of 36°30′, and then the notorious proslavery Lecompton state constitution for Kansas by which Buchanan tried (but failed) to bring Kansas into the Union as a slave state in 1858. Both supported the Confederacy during the Civil War.


William Gwin’s chief challenger for control of California’s Democratic Party was David Broderick, a New Yorker who opposed the Chivalry’s proslavery tilt. Broderick was a hardened political fighter who had learned his trade in the rough politics of New York City before migrating to California. But he proved no match for the Chivs, who outmaneuvered him to gain the support and patronage of the Buchanan administration even though Broderick managed to get himself elected to the Senate in 1857. His tenure there was short-lived. In 1859 a political mudslinging match between Broderick and David Terry, a Texan who had arrived in California in 1849 and became a prominent Chiv, led to a duel. Terry resigned from his post as chief justice of the California Supreme Court in order to challenge Broderick. Winning the coin toss for choice of weapons, Terry selected pistols with hair triggers that he had brought with him. Unaccustomed to these weapons, Broderick fired too soon and wildly, whereupon Terry took careful aim and shot him dead. This was the third duel in California during the 1850s in which a Chiv Democrat killed a member of the anti-Chiv faction of the party.

In addition to killing off the opposition, the Chivalry made repeated efforts to infiltrate slavery into California—or at least into part of it. In 1852 the legislature enacted a law that permitted a slave owner to “sojourn” indefinitely in California with his human property, and the two justices on the state Supreme Court who hailed from slave states upheld it. The law was renewed in 1853 and 1854 before finally lapsing the following year. By then the proslavery forces had come up with a new idea: to divide the state in two, with the southern portion reverting to territorial status and open to slavery like New Mexico and Utah.

All of the gold mines were in the northern part of the state, so there was no more talk of slavery’s adaptability to mining. Instead, according to the Chivs, slaves in southern California could grow “Cotton, Rice, & Sugar.” By “this peculiar labor,” they said, California’s “valuable soils” could be “rendered productive.” In 1859 the state legislature enacted a bill providing for splitting off southern California at approximately the latitude of San Luis Obispo, subject to a two-thirds majority vote in a referendum in the affected counties. They voted for it by almost three to one, but when the measure reached Congress at the end of 1859 it died a quiet death in the House, where the Republicans were now the largest party. For better or worse, California remained one state.

California’s admission as a free state had given an impetus to one of the more bizarre phenomena of the 1850s—“filibustering,” after the Spanish word filibustero, a freebooter or pirate. A new slave state was needed to offset California. The leaders of the Polk administration had not been satisfied with the acquisition of Texas and the Southwest. They wanted Cuba as well, where planters restive under Spanish colonial rule looked to the Americanos. Several Southern politicians were strongly drawn to the prospect of adding Cuba with its almost 400,000 slaves to the United States. Spain refused to sell, however, so a private army of American filibusterers led by the Venezuelan-born Cuban soldier of fortune, Narciso Lopez, invaded the island twice, in 1850 and 1851. The first time Spanish soldiers drove them back to their ships; the second time they killed two hundred of the invaders and captured the rest. They garrotted Lopez in the public square of Havana and killed fifty-one American prisoners by firing squad, including William Crittenden, nephew of the attorney general.

This experience put a damper on filibustering expeditions to Cuba. The scene shifted three thousand miles west to California itself. In 1857 Henry Crabb, who had migrated to California from Mississippi and had joined the Chivalry wing of the Democratic Party, led a filibustering invasion of the Sonoran province of Mexico. Mexican troops ambushed them, killed or wounded twenty-one filibusterers, and executed fifty-nine others, including Crabb. The all-time filibuster champion was William Walker, a Tennessee native who also turned up in California in 1849. A failed invasion of Baja California in 1853 did not discourage him. In 1855 Walker led an army of two thousand American filibusterers into Nicaragua, where in alliance with local rebels he gained control of the government in 1856, named himself president, and reinstituted slavery. But a coalition army from other Central American countries overthrew his regime. After several attempts to return, he was captured and executed by Honduran troops in 1860.

All of the filibuster efforts to organize another slave state in order to offset California came to grief. They did succeed, however, in exacerbating the controversy over the expansion of slavery. Meanwhile, Minnesota and Oregon came in as free states in 1858 and 1859. By the latter year the South had also lost its campaign to make Kansas a slave state. The balance of power permanently tipped against the South, which strengthened the influence of those who clamored for disunion. This process, which had begun with the loss of California to freedom in 1849, is the implicit theme of The California Gold Rush and the Coming of the Civil War. Richards never makes the theme explicit, however. The central thread of his narrative is the colorful and violent history of internal California politics in the 1850s.

If Richards had made his title theme explicit, the argument would have gone something like this: The discovery of gold in California produced a mass migration there in which settlers who wanted to exclude slavery prevailed. Their application for statehood provoked a polarizing sectional debate in Congress that produced threats of secession if the South did not get its way. The Compromise of 1850 papered over these divisions temporarily, but tension continued to simmer, and burst into flame again with the Kansas-Nebraska Act in 1854. That crisis might not have occurred, at least so soon, without the perceived need for a railroad to connect California to the Mississippi Valley.

Repeal of the ban on slavery north of 36°30′ was the price that Senator Stephen Douglas had to pay for Southern support of the territorial organization of Kansas and Nebraska, through which the railroad would be built. The dominance of the Chivalry faction in California politics invigorated the proslavery element in the national Democratic Party, whose overweening grasp for power in the effort to make Kansas a slave state alienated Northern voters and strengthened the antislavery Republican Party. So did the filibustering expeditions, several of which originated in California. Of course, tensions between North and South had existed before California became part of the United States and would probably have intensified in the 1850s even if gold had never been discovered there. But the precise shape of the sectional conflict that led to secession and war in 1861 was surely influenced by the California story.

Within California itself, perhaps the first shot of the Civil War came from David Terry’s hair-trigger pistol that killed David Broderick in September 1859. The backlash against what many Californians saw as a political assassination weakened the Chivs and redounded to the advantage of the state Republican Party, which had never previously gotten more than 23 percent of the vote. In 1860 Abraham Lincoln won a plurality of 32 percent of California’s votes in the four-party contest and came away with the state’s four electoral votes. During the Civil War most Californians remained loyal to the United States, and the state’s shipments of gold helped finance the Union war effort.

Several prominent Chivs, however, went South. One of them was David Terry, who had suffered no legal punishment for his killing of Broderick. He fought with the 8th Texas Cavalry and was wounded at Chickamauga. He returned to California in 1868 to practice law and dabble again in politics. In 1889, exactly thirty years after he had killed a United States senator, Terry became embroiled in a dispute with another California political rival from the 1850s. This time it was Stephen J. Field, who had been appointed by Lincoln as an associate justice of the United States Supreme Court in 1863. In 1888, Field, as senior justice of the California circuit court, presided over a lawsuit by Terry’s second wife against her former husband, a Nevada senator. When Field jailed Terry and his wife for contempt, Terry vowed revenge. The US marshal assigned a bodyguard for Field. The following year Terry encountered Field in a railroad station near Stockton and slapped his face (as a challenge to a duel, presumably). The bodyguard shot Terry dead. Perhaps this was truly the last shot of the Civil War.

This Issue

October 11, 2007