Long before the appearance of Europeans in the area now known as the American Southwest, various indigenous groups knew specific areas extremely well. Nomadic tribes, in particular, were familiar with limited areas of the region’s rugged landscape, but so were more sedentary peoples, such as those at Acoma, New Mexico, who can claim continuous human habitation there for at least a thousand years.
The arrival of the Spanish in the sixteenth century initiated a period of inland exploration that put this native geographical knowledge into the larger context of continental cartography. Nevertheless, Spain was interested primarily in the area around Mexico City, and for more than two centuries the generally arid and thinly populated frontier to the northwest remained a remote outpost in its empire. Alexander von Humboldt took note of this neglect following an expedition to the New World early in the nineteenth century. Humboldt, whose largely compiled 1811 map of New Spain was the best of its kind for several decades, exhorted the Mexicans to occupy the area, but his advice generally went unheeded.
The United States began exploring the continent beyond its formal boundaries in earnest under President Thomas Jefferson, to whom Humboldt had apparently conveyed his thoughts about the Southwest during a visit to Washington, D.C., in 1804. The first efforts, however, focused on the upper Rocky Mountain area and the Pacific Northwest. Although individual mountain men knew portions of the Southwest’s geography quite well, and a number of expeditions reconnoitered part of the area, contemporary maps of the region tended to be either compiled from earlier, often inaccurate sources or based on rough surveys.
The establishment of the U.S. Army Corps of Topographical Engineers in 1838 ushered in a new era of geographical discovery in North America, wrote the historian William H. Goetzmann. Beginning in the 1840s the Topographical Engineers, a group of highly trained military geographers armed with the latest equipment, methods, and techniques, mounted numerous expeditions that resulted in the first systematic surveying of vast stretches of the American West.
Among those who comprised the corp’s first group of officers was William Emory. In 1846, after war broke out with Mexico, Emory joined the Army of the West as Colonel Stephen Kearny’s topographical engineer. The army was ordered to secure a route across New Mexico to the Pacific Ocean, thus protecting a vital communication and supply link to American forces in occupied California. For the Topographical Engineers, it was an unprecedented opportunity for important original exploration.
Given only twenty-four hours notice, Emory hastily gathered his equipment and departed for Fort Leavenworth in Kansas. A trained engineer and mathematician with extensive surveying and mapping experience in both the field and the office, he was ready to make his most original contribution to the cartography of the American Southwest: the first detailed, instrumental survey from eastern Kansas to coastal California.
William Hemsley Emory seemed almost preordained to fulfill the role of soldier-scientist. He was born on 11 September 1811 at his family’s estate in Maryland, Poplar Grove, which the wealthy and influential Emorys had owned since colonial times. Following a family military tradition, young Emory was sent to West Point, to which he had received an appointment at the age of eleven. There he befriended, among others, Jefferson Davis, Joseph E. Johnston, and Henry Clay, Jr. and acquired the nickname “Bold Emory” for his daring.
After graduating in the class of 1831 as a second lieutenant, Emory was assigned to the Fourth Artillery. He served at a number of forts in Maryland, South Carolina, and New York, but found garrison duty boring and unrewarding. In 1836 he resigned his commission to become an assistant U.S. civil engineer. Ironically, it was this experience as a civil engineer that ultimately made him eligible for appointment to the Corps of Topographical Engineers.
Emory flourished in the corps. Under the aggressive leadership of Colonel John James Abert, the topographical engineers were expected to obtain military intelligence, conduct topographical surveys, and record observations of natural and human phenomena while in the field. These responsibilities coincided with Emory’s increasing interest in science, and the young officer began adding to his circle of friends from the leading American astronomers, mathematicians, geographers, and natural scientists of the day. He became an expert on harbor improvements and from 1839 to 1842 worked on a project along the Delaware River. The following year he moved to the Topographical Bureau in Washington, and from 1844 to 1846 he served on the Northeastern Boundary Survey, which was charged with determining the border between the United States and the northern British provinces.
Emory’s careful, methodical approach contrasted sharply with the aggressive and self-promoting style of John Charles Frémont, one of Emory’s colleagues in the corps and one of its few members who was not a graduate of West Point. Frémont had gained his mapping experience under Ferdinand V. Hassler at the U.S. Coast Survey and especially as field assistant to Joseph N. Nicollet during the latter’s important survey of the upper Mississippi Valley in 1836–40, and he later went on to become one of the most well-known explorers of the West. But it was Emory, not Frémont, who brought Nicollet’s survey to publication form as the Hydrological Basin of the Upper Mississippi River from Astronomical and Barometrical Observation Surveys and Information in 1843, an influential map authorized by the War Department and published by the U.S. Senate. And it was Emory who the following year published a compiled Map of Texas…, with a detailed accompanying Memoiroutlining the claims of the United States in the Southwest. It, too, was transmitted to the U.S. Senate.
Emory arrived at Fort Leavenworth in June 1846. His equipment included two excellent box chronometers (Nicollet had measured the longitude of Fort Leavenworth as 94? 44’00”W), a siphon barometer with which to ascertain elevation above sea level, a viameter for measuring distances, and two sextants. He also had a number of previously published maps, including four copies of his own map of Texas, as well as two nautical almanacs and two sets of Haswell’s tables.
Kearny’s main force left Fort Leavenworth in late June and headed southwest on the trail to Santa Fe by way of Bent’s Fort on the Arkansas River. A month later the troops reached the fort and then started the march south. As they moved over the Raton Pass and across Vermejo Creek, Emory noted the arid countryside and its poor prospects for farming. He also confirmed an earlier report about coal deposits along the trail and even speculated that the whole area was once a plateau but had been worn away by some “denuding process” that had left little other than volcanic rock. After a stop in the ancient town of Pecos, Emory entered his first detailed descriptions of the peoples and antiquities of the Southwest. Goetzmann described Emory’s observations as the “crude beginning” of American anthropological and archaeological studies in the West.
The Americans took Santa Fe peacefully on August 18. It was a measure of Emory’s multiple roles, particularly in wartime, that he was expected to select and survey a site for a fort, make observations about the political, social, economic, and religious life of the community, and commence work on a map charting the route the army had followed to this point. He also took time to note the military and commercial importance of the New Mexico region, not least as a southerly route for a trans-continental railroad.
On September 25 Kearny, based on what would later prove to be poor intelligence, split his forces and struck out for California. Kearny’s group, which included Emory’s fourteen-man topographical unit, headed southwest and then west along the Gila River. Only a few Americans, such as Kit Carson, the frontier scout who had joined Kearny’s reduced force, were acquainted with the area. In the tortuous valley of the Gila, as elsewhere, Emory recorded the length of each day’s journey, longitude, latitude, and, where possible, elevation above sea level. At times the Gila was so constricted that Emory and his crew had to leave the canyon and ascend the surrounding tablelands. But Emory was fascinated by the ruined pueblos, abandoned water works, broken pottery, and antique hieroglyphics they encountered in the volcanic dust and rocky basalt.
Emerging from the gorge the army proceeded westward to the confluence of the Gila and the Colorado River, which they forded without great difficulty. Emory paused to calculate the position of the junction with his astronomical instruments. After discovering fresh tracks heading northward, he led a patrol that surprised a Mexican camp, where the Americans captured a colonel and several soldiers with a herd of about a thousand horses. The next day Emory’s group captured a Mexican courier, who informed the Americans that an uprising in California had resulted in the fall of Santa Barbara and Los Angeles.
Kearny realized the necessity of reaching California as quickly as possible and drove his forces hard across the harsh California desert. On December 2 the exhausted and starving men finally reached the mostly inland coastal range and three days later arrived at a ranch named Santa María. On December 6, at San Pasqual, a troop of Mexican cavalry attacked the Americans. Emory fought bravely and even rescued Kearny from certain death, but the Americans suffered greatly, with eighteen dead and thirteen others wounded. The Mexicans suffered only two casualties.
Under cover of darkness Kit Carson journeyed to San Diego, where the U.S. Navy was in control, to obtain assistance. On December 12, after several more tense confrontations during which Emory distinguished himself further (he would receive two field promotions for his bravery), the Army of the West limped into San Diego. Here Emory compared his longitudinal observation with that of Captain Sir Edward Belcher of the British Royal Navy, who happened to be in port. After a land journey covering nearly two thousand miles and spread out over approximately six months, Emory’s observation differed only minimally from Belcher’s (117? 11’00”W) whose determination he accepted, as he had Nicollet’s in Leavenworth. Prior to this no point of land between the upper Rio Grande and the Pacific Ocean had been determined with precision and so recorded on a map.
With reinforcements the Americans marched northward and took the little pueblo of Los Angeles on 9 January 1847. Emory made no additional observations because the coast was relatively well mapped, as he noted in his record. On January 25 he boarded a ship to return to Washington via Panama. He had become the first American scientist to travel across the Southwest, and he had compiled a detailed and accurate record of the trip.
Emory’s experience in the Southwest led to his appointment in 1848 to determine the boundary of the territory acquired by the United States under the Treaty of Guadalupe Hidalgo. He was largely responsible, on the American side, for the demarcation of the two-thousand-mile-long United States–Mexico international boundary. He later fought with distinction as a Union general in the American Civil War and served as commander of the Department of the Gulf during Reconstruction.
But Emory’s greatest and enduring achievement was his scientific surveying and mapping of the American Southwest. His map, Reconnaissance of the Arkansas, Rio del Norte and Rio Gila, 1847, compiled from more than two thousand astronomical observations and 350 barometric readings, was, according to one scholar, “the final major piece needed to complete the early outline of trans-Mississippi geography.” The noted scholar Carl Wheat called it “a document of towering significance in the cartographic history of the West.” William Goetzmann wrote that it “corrected errors in Humboldt’s atlas, modified Frémont’s map of 1845, and rendered the commercial maps of Mitchell and Tanner immediately obsolete.” Other cartographers of the time, such as Frémont, who used Emory’s data for his later maps without crediting the source, and Emory’s subordinate G. Kemble Warren, with whom Emory has often been compared, depended heavily on his observations.
Moreover, in his Notes on a Military Reconnaissance, published along with his map in 1848 as an official Senate document, Emory provided the American public as well as his fellow scientists with the first systematic look at the Southwest. Ranging widely over geology, botany, ethnology, archaeology, politics, and economics as well as geography, he made his mark as a first-rate scientist whose observations would have a significant and lasting influence on social and economic policy in the West.
Emory Peak in Texas’s Big Bend Country honors Emory’s work on the international boundary survey, and one of the plants he collected during the 1846–47 survey is now known as Quercus emoryi. He was an exemplar of the kind of soldier-scientist envisaged when the Corps of Topographical Engineers was created. In the end, as historian Martha Bray astutely observed, “Emory and not Frémont was Nicollet’s last true disciple.”
Norman J.W. Thrower is Professor Emeritus in the Department of Geography at the University of California, Los Angeles.
Illustrations courtesy of Norman J.W. Thrower
Bray, Martha Coleman. Joseph Nicollet and His Map.Philadelphia: American Philosophical Society, 1980.
Emory, William H. Notes of a Military Reconnaissance.Washington, D.C.: Wendell and Van Benthuysen, 1848.
Emory, William H. “Reminiscences of General William Hemsley Emory U.S.M.A. 1831.” MS #4126 6648. West Point: U.S. Military Academy Library.
Goetzmann, William H. Army Exploration in the American West 1803–1863. New Haven: Yale University Press, 1959.
Goetzmann, William H. Exploration and Empire: The Explorer and the Scientist in the Winning of the American West.New York: Alfred A. Knopf, 1966.
Schwartz, Seymour I., and Ehrenberg, Ralph E. The Mapping of America. New York: Harry N. Abrams, 1979.
Thrower, Norman J.W. How the West Was Mapped: The Cartography of the North American Southwest from Waldseemüller to Whitney.Milwaukee: American Geographical Society, 2001.
Thrower, Norman J.W. “William H. Emory and the Mapping of the American Southwest Borderlands.” Terrae Incognitae 22(1990): 41–91.
Wheat, Carl I. Mapping the American West, 1540–1857.Worcester, Mass.: American Antiquarian Society, 1954.
Wheat, Carl I. Mapping the Transmississippi West, 1540–1861. San Francisco: Institute of Historical Cartography, 1957–63.