to grow year-round market crops for export, with only the occasional river valley providing the appropriate ecosystem for agricultural production.
In New Mexico, only three such rivers—the Chama, the Pecos, and the Rio Grande—provided enough water to support farming on any significant scale, and even then irrigation was necessary in most places and for most crops.32 Taken collectively, the farmlands in those three valleys composed an infinitesimal fraction of the total land area, and that tiny percentage was in turn subdivided into hundreds of long-lots of twenty to forty acres each, based on family inheritance of property, a distributive tradition that traced its origins back to colonial land grants. Most of northern New Mexico was therefore relegated to a pastoral economy based largely on sheep-raising and wool harvesting. This combination of pastoralism on the grassy hillsides and at higher elevations, along with agriculture in the more arable valleys and lowlands, necessitated involuntary labor in the form of Indian captives and Hispanic peons. The number of man-hours needed to sustain the Southwest’s seasonal subsistence economy, however, never remotely approached what was required for export-driven cotton and tobacco plantations in the South.
New Mexico also operated in large part on what historian Dan Usner has called a “frontier exchange economy,” with Hispanos obtaining many of their goods through barter-driven trading networks that involved peripheral Indian tribes.33 Exemplified by the trade fairs at Pecos and Taos, this component of the southwestern economy involved the exchange of animals, food, and items of Native manufacture for staples of Euro-American origin and captives. In this sense, mid-1800s New Mexico lacked the telltale features of western capitalism—industrialization, the capacity for mass production, and extractive market resources—that many American newcomers hoped to encounter there. What they discovered instead was a variegated economic system that included hunting and gathering, pastoralism, subsistence agriculture, involuntary servitude, and even the extension of credit in the form of merchandise, but rarely the circulation of hard currency or bank notes.34 Despite the advent of the Santa Fe Trade in 1821 and the concomitant commercial network established with Missouri merchants, New Mexico remained a quasi-feudalist society with a hierarchical social order—a primitive civilization, in the eyes of most American newcomers—that hardly beckoned for the implementation of chattel slavery and market agriculture on a grand scale. Southern efforts to extend slavery westward were in large part a political ploy to secure additional proslavery representation in Congress and to prevent any significant dissolution of the peculiar institution in places where it already existed.
Southerners valued the Southwest primarily for its geographic and political importance, not because they hoped to establish profitable plantations and transport large numbers of black slaves there, although this was the very ideological objective to which they turned during debates on the topic. Since New Mexico linked slaveholding Texas with Southern California, the region would complete an uninterrupted coast-to-coast empire should the South succeed in conquering New Mexico and California at the onset of a civil war. During his tenure as secretary of war in the 1850s, the future Confederate president Jefferson Davis commissioned the Pacific Railway Surveys and endorsed the Gadsden Purchase in advancement of a futuristic Southern strategy that saw New Mexico as the location of a transcontinental railroad linking the Gulf of Mexico to the Pacific Coast.35 Thus, Southern attempts to establish and uphold the right of slaveownership in New Mexico were predominantly ideological, a strategic machination seeking sectional geographic expansion not for the purpose of implanting chattel slavery and plantation agriculture, but rather for establishing a continental empire that would enable Southern cotton to be more easily exported worldwide.
Some politicians readily acceded to the fact that the southwestern environment did not appear conducive to chattel slavery or plantation agriculture. Speaking to Congress in 1848, George P. Marsh, a Vermont representative, stated that the Mexican Cession lands “lie without the natural limits of slavery, and the institution cannot exist in those provinces, because it is excluded by physical conditions, and the economical law of profit and loss which they dictate.” In their arguments against slavery, some abolitionists and free-soilers contended that the Southwest, with its subsistence agriculture and pastoral economy, must “be inhabited and tilled only by freemen” because the absence of labor-intensive export crops like rice, cotton, sugar, and tobacco precluded any extensive demand for manual slave labor.36 That observation, while partially true, also assumed that slavery existed in only certain environments where particular crops grew, a fallacious notion that neglected to account for the thousands of unfree peons and captives toiling in southwestern fields, pastures, and households. Expounding upon Marsh’s claims, Senator Truman Smith pledged that New Mexico “will and must be [a] free state, proviso or no proviso,” referencing the provocative but moribund proposal of Representative David Wilmot in 1846.37 As supporting evidence, Smith introduced published travelogues and reports from the Army Corps of Topographical Engineers to describe the southwestern climate. All of these firsthand accounts sustained the contention that chattel slavery could not profitably exist in the arid deserts and high altitudes of New Mexico and Utah.38 Describing the Santa Fe region, Lieutenant William H. Emory reported quite bluntly that it “presents nothing but barren hills, utterly incapable, both from soil and climate, of producing anything useful.”39 Even Southerner Henry Clay, in attempting to lead a highly factionalized Congress to a compromise measure in 1850, pointed out that New Mexico, with its dry climate, had nature itself on her side, which he equated to “a thousand Wilmot Provisos.”40
Senator John Bell from Tennessee joined antislavery congressmen in alluding to the dryness of the Southwest, proclaiming that “African slavery can never find a foothold in New Mexico.”41 Even if territorial residents favored slavery in practice, in principle, or both, Southerners would be unlikely to transport chattels there because, according to one Pennsylvania senator, “Masters will hardly carry their slaves into a territory in which they will be likely to be free as soon as their feet touch its soil.”42 In making such claims these politicians reasserted the statements of a New Mexico congressional delegate, Hugh N. Smith, who in April 1850 acknowledged the region to be “entirely unsuited for slave labor.” Smith then paradoxically admitted that debt peonage, existing “in a quantity quite sufficient for carrying on all the agriculture of the territory,” effectively fulfilled regional demand for labor.43
During discussions over a proposed compromise measure, Bell’s antislavery colleague, Senator Daniel Webster, remarked that “no man would venture a farthing today for a great inheritance to be bestowed on him when slavery should be established in New Mexico.”44 Longtime New York politician Washington Hunt sarcastically offered a reward of $1,000 “for the discovery of a slaveholder who even wished to take his slaves thither.”45 Others refused even to lend credence to the issue, believing the impracticality of slavery in the Southwest to be so obvious that it scarcely warranted their time and attention. By invoking the climate as an argumentative point, such claims reverberated around the more familiar plantation slavery and maintained that, so long as irrigation was needed to grow crops, slavery could not logically or profitably exist. This Northern Whig stance offered a practical nature-based alternative to the ideological abolition movement, which many saw as overly incendiary and antithetical to preserving the Union.46
Webster commended fellow Northerner Truman Smith for having adequately proven, “beyond the power of any conscientious man’s denial,” that slavery could never exist in New Mexico and for demonstrating to Northerners “that that which they desire to prohibit will never need any prohibition there.”47 He then insisted that the debate should proceed no further because “there is not, & there cannot be slavery” in California, New Mexico, or Utah.48 Webster remained convinced that New Mexicans, “to a man, are opposed to slavery” and believed all territorial inhabitants to be “as warmly and decidedly” averse to it as the people of Maine were. The statesman assured his listeners that “slavery of the African race does not exist in New Mexico” and explained that the social and economic atmosphere of the region had no need for such a system because “the use of cheaper labor [peonage] rejects it.” Invoking a final hyperbolic analogy, Webster swore that
