Senator Benton, who claimed to have been averse to slavery in principle since early adulthood, concurred in the view that Mexico’s antislavery provisions had not been automatically repealed when the southwestern domain shifted to American jurisdiction. In New Mexico and California, he pointed out, slavery had already been abolished at the time of the American conquest and could be reintroduced there only if Congress passed a new law to that effect.96
Addressing political colleagues on July 8, 1850, Senator Truman Smith offered a detailed description of slavery laws in New Mexico, beginning his diatribe with the straightforward comment that slavery had been prohibited there prior to the region being ceded to the United States. “If the ordinances and laws of Mexico abrogating slavery do not continue, yet it may be assumed that there is no law authorizing it,” he reasoned, “and this is just as serious an obstacle to the introduction [of slavery] as a positive law forbidding it.”97 Because Mexican statute applied to the region at the time of the American conquest, Smith contended that those laws remained valid and enforceable, and by simply recanting such edicts Congress could not “reintroduce slavery” without passing an entirely new law to that effect.98
Still other Northerners feared that previous Spanish and Mexican mandates outlawing slavery would prove insufficient in preventing its eventual extension into the Southwest, demanding that Congress enact additional measures to ensure that black men and women could never be taken to those territories as slaves. Representative Marsh again questioned the validity of Mexico’s laws, warning fellow Northerners about the veracity of such abolitionist doctrine and suggesting that U.S. courts would be unlikely to recognize another nation’s legal codes. Skeptical of what judges might rule in the event of litigation, he cited this ambiguity as sufficient justification for the enactment of additional measures outlawing slavery in the Southwest.99
Marsh focused on Mexico’s 1824 federal constitution, which he claimed had regulated slavery but not abolished it entirely, because the document banned involuntary servitude only in that republic’s states. New Mexico and Alta California had been provinces—similar to territories in the U.S. body politic—and it remained a matter of interpretation as to whether the Mexican constitution had indeed outlawed slavery there along the same lines as the more southerly states. Subsequent laws passed in 1829 and 1837 were also questionable in their ultimate effect, in part due to civil and social unrest in that country. The general instability of Mexico’s government made it difficult for American lawmakers to determine whether or not that country’s congressional bodies even had the power to pass acts that superseded the 1824 constitution.100
These legal loopholes jeopardized the Northern movement to ban slavery in the Southwest. “Though slavery may have been abolished by Mexico,” Marsh concluded, “yet American slaveholders may now revive it, by removing to the Territories and carrying their slaves with them,” a possibility that, however unlikely, nonetheless necessitated congressional action.101 Broadcasting the Southern viewpoint, Senator Calhoun sprang to his feet and condemned all antislavery interpretations of New Mexico’s legal situation. At the moment Congress ratified the Treaty of Guadalupe Hidalgo in 1848, he insisted, Mexican sovereignty “became extinct” in the ceded territory and the U.S. Constitution took effect.102 As one of the most vocal and preeminent proslavery representatives of his time, Calhoun voiced the sentiments of many Southerners when he asserted the irrelevance of all Mexican laws. Their Northern counterparts had, they believed, strayed woefully awry in embracing the notion that another country’s statutes prohibited the extension or regulation of slavery within the American national domain.
Jefferson Davis, at the time a U.S. senator from Mississippi, likewise deflected the Northern argument with his own forceful invective. “Did we admit territory from Mexico subject to the constitution and laws of Mexico? Did we pay fifteen millions of dollars for jurisdiction over California and New Mexico, that it might be held subordinate to the law of Mexico?” the senator asked rhetorically during a February 1850 speech.103 Davis recalled the negotiation process antecedent to the signing of the Treaty of Guadalupe Hidalgo, during which time a United States minister plenipotentiary, Nicholas Trist, discussed the slavery issue with Mexican commissioners. Trist purposely sidestepped the topic of slavery in the actual treaty to avoid setting a controversial precedent, informing his ambassadorial counterparts that “the bare mention of [slavery] in any treaty … was an absolute impossibility.” He understood that any provision either including or excluding slavery in the ceded territory could not be considered without inciting political turmoil in the halls of Congress. Trist only slightly exaggerated the gravity of the situation when he told Mexican diplomats that “if it were in their power to offer me the whole territory described in our project, increased tenfold in value [and] covered a foot thick over with pure gold, upon the single condition that slavery be excluded therefrom, I could not entertain the offer for a moment, nor think even of communicating it to Washington.”104
Figure 5. John C. Calhoun, proslavery South Carolina senator. Courtesy National Archives and Records Administration, Washington, D.C.
Davis alluded to this intentional omission of Mexico’s slave laws as evidence that such mandates could not remain in effect after the treaty had been signed. He quoted the constitutional recognition of slave property as validation for the Southern cause, noting that the founding document ensured all American citizens the same legal protections regardless of sectional affiliation. Mexico’s abolition of slavery during the 1820s, he insisted, became irrelevant the moment that it ceded New Mexico and California to the United States, whereupon that entire region came under “a sovereignty to be measured by our Constitution, not by the policy of Mexico.”105
The most comprehensive analysis of preexisting Mexican laws and their impact on the extension of slavery into New Mexico came from Judge Kirby Benedict. Explaining his ruling in an 1857 peonage case, Benedict expounded upon previous Spanish and Mexican slavery statutes, analyzing the intended effects of those laws and addressing many of the same unresolved issues that congressmen had raised several years earlier. Benedict began by acknowledging the longtime existence of debt peonage in New Mexico. Comparisons first had to be drawn between the common perceptions (and misperceptions) of peonage versus slavery as institutions of involuntary servitude. Identifying them as essentially one and the same system in principle, Benedict opined that slavery “ceased to exist” during the Spanish colonial era, citing an act of Spain on August 6, 1811, as the official moratorium. Spanish law thereafter prohibited any person from selling another’s liberty or engaging in any other act that might be perceived as human trafficking. In Benedict’s estimation, all forms of involuntary servitude had been banned in New Mexico by decree of its mother country in 1811.106
After gaining independence in 1821, Mexico’s lawmakers passed their own edicts defining and regulating slavery, all of which reinforced previous Spanish law and included additional sanctions for violations. According to Benedict, such legislation demonstrated “the Mexican spirit” on the topic of slavery and would be the guiding principle for his pending legal interpretation.107 Mexico’s 1829 decree defined master-servant relationships, acknowledged the existence of servitude, and placed numerous restrictions upon masters. Nobody in Mexico would ever again be born into slavery, and six months after the law’s inception “the introduction of slaves” would be forever prohibited.108 The law also forbade whipping and other forms of corporal punishment, with a provision allowing servants and slaves to sue an abusive master for “excessive chastisement.”109 This and other Mexican statutes applied equally to New Mexico and had effectively banned racial slavery—while specifically allowing peonage—many years prior to the 1846 U.S. conquest.
Having thus established the parameters of preexisting Spanish and Mexican laws relative to slavery in New Mexico, Benedict examined the territory’s midcentury transition in sovereignty. He cited the inception of the Kearny Code in September 1846 as the first instance of American law being implemented, noting that the document
