Walker, Juan Pedro (1781–ca. 1828)

By: Elizabeth A.H. John

Type: Biography

Published: January 1, 1996

Updated: February 16, 2019

Juan (John) Pedro Walker, pioneer cartographer, was born in Spanish New Orleans on January 19, 1781, to English immigrant Peter Walker and French New Orleans native Charlotte Constantia Revoil. Reared principally in Spanish Natchez, where his father established a mercantile business in the mid-1780s, Juan Pedro Walker was hired at age seventeen as chain bearer on the United States crew for the joint United States-Spanish survey that marked the thirty-first parallel as the boundary between Spanish Florida and the United States. Walker's work on that survey, from the Mississippi River to the Atlantic, 1798–1800, constituted apprenticeship in field surveying and contemporary techniques of cartography under Boundary Commissioner Andrew Ellicott, then the foremost cartographer in the United States. Upon completion of the survey, Ellicott engaged Walker to assist him in preparing for publication the voluminous maps and charts to be derived from the survey. Hence, Walker sailed with Ellicott to Philadelphia, where he studied at the Philadelphia Academy in addition to drafting geographical documents under Ellicott's supervision, 1800–1801. Returning home to find Natchez in turmoil under United States territorial government, Walker preferred Spanish governance. In 1802 he became a recognized surveyor in the Concordia district of Spanish Louisiana; by 1803 he was the official surveyor of that jurisdiction. While in Spanish Texas to fulfill a construction contract for the Nacogdoches parish church, Walker learned in August 1803 that the United States had purchased Louisiana. As a lifelong subject of the Spanish crown, he promptly applied for permission to move to the Provincias Internas of New Spain. Walker was readily welcomed for his valuable skills and received permission to settle in Texas but was urged to proceed instead to Coahuila, where Governor Manuel Antonio Cordero y Bustamante recruited him for the Spanish service. Walker enlisted on March 28, 1804, as a cadet in the Mobile Company of Parras; by autumn he was back in Texas, surveying and mapping along the Rio Grande and the Río Guadalupe. On January 15, 1805, he was commissioned second alférez in the Presidial Company of Janos and soon demonstrated his mapping skills on the margins of the Bolsón de Mapimí, which he traversed with an expedition from Janos. In the spring of 1805 Walker was transferred to Chihuahua to serve at the headquarters of Commandant Gen. Nemecio Salcedo y Salcedo, as cartographer, translator, and director of the commandancy's small military school.

At Chihuahua, 1805 to 1811, Walker's foremost responsibility was the production of maps, based on evidence in the archives of the commandancy general as well as his own fieldwork, to document Spain's historic territorial claims in the northern reaches of New Spain, which were then threatened by counter-claims from the United States. However, from June to October 1806 he was seconded to the Nacogdoches area at the request of Spanish officers calling upon his knowledge of the Americans to help avert the threat of war on the Texas-Louisiana frontier. Walker's cartographic work was again interrupted in April 1807, when Commandant General Salcedo designated him as residential host to Lt. Zebulon M. Pike, as well as interpreter for Pike's party during their involuntary sojourn in Chihuahua and as transcriber/translator of their confiscated documents. Information gleaned from maps seen at Walker's quarters figured in maps subsequently published by Pike (1810) and his companion, Dr. John Robinson (1819). Walker's career collapsed on January 30, 1811, when Commandant General Salcedo jailed him at Chihuahua on charges of supporting the independence movement of Father Miguel Hidalgo y Costilla. Walker was convicted by a military tribunal on November 29, 1811, stripped of military employment, and condemned to perpetual exile from America. He was to be confined in frontier presidial barracks until the insurrection should subside enough to permit his transport to Veracruz for shipment to Spain. Walker's fortunes improved in 1814, after the Commandancy General of the Interior Provinces was divided into eastern and western commandancies. The commandant general of the eastern provinces, Joaquín de Arredondo, brought Walker to his headquarters at Monterrey to address the urgent need for accurate maps of that jurisdiction. During 1815 and 1816 Walker engaged in extensive, onerous fieldwork along sectors of the Rio Grande, the Texas interior as far north as San Antonio, and the coast of Nuevo Santander, as well as working in Monterrey on the compilation of maps from all the resources that could be mustered at Arredondo's headquarters.

Meanwhile, the new commandant general of the western provinces, Bernardo de Bonavía y Zapata, reviewed Walker's case and found that Salcedo had erred in prosecuting it as a military rather than a civil offense. The error could be redressed only by the highest authorities in Spain, where Walker was shipped, under arrest, from Veracruz early in 1817. Once prisoner Walker arrived at the military jail in Cádiz, his petitions and documents were forwarded to superior authorities who soon ordered that he be set free, informed of the state of his case, and permitted to make representations. Walker appealed vigorously. The ultimate decision was that verification and punishment should have been under local civil authority, but that the matter could not be rectified at such distance in time and space. Lacking sufficient evidence either to convict or to exonerate Walker, the crown required that he select a permanent domicile anywhere in Spain other than a port or the vicinity of the seat of government, but provided that, as a former officer, he would receive a small stipend. Walker moved to Valladolid, where he lived another decade as a pensioner of the Spanish crown.

Although none of Walker's maps was published, the unusual rapidity of his promotions, from cadet to alférez in 1805 to sub-teniente in 1808 to teniente in 1809 and ayudante mayor in 1810, attests the value that his superiors saw in his work. The scope and character of his cartography can be traced through extant manuscript maps and fragmentary field notes, contemporary allusions to his maps in official correspondence, and maps published in the United States that cited Walker as their source for new information on the Pacific coast and Mexico. Fifteen Walker maps identified thus far in repositories in Spain, Mexico, and the United States run the cartographic gamut, from rough drafts with scribbled calculations to elaborately detailed final products. The scope of these extant maps ranges from limited sectors reflecting his own fieldwork-e.g., one of the Big Bend area and another of the Rio Grande from Laredo to the mouth of the Río Salado-to maps of entire provinces or groups of provinces and two that present remarkably up-to-date knowledge of central and western North America from Hudson's Bay to the tip of Baja California and the Mississippi River to the west coast.

Elizabeth A. H. John, "The Riddle of Mapmaker Juan Pedro Walker," in Essays on the History of North American Discovery and Exploration, ed. Stanley H. Palmer and Dennis Reinhartz (College Station: Texas A&M University Press, 1988). Carl I. Wheat, Mapping the Transmissippi West, 1540–1861 (San Francisco: Institute of Historical Cartography, 1957–63).

The following, adapted from the Chicago Manual of Style, 15th edition, is the preferred citation for this entry.

Elizabeth A.H. John, “Walker, Juan Pedro,” Handbook of Texas Online, accessed June 26, 2022, https://www.tshaonline.org/handbook/entries/walker-juan-pedro.

Published by the Texas State Historical Association.

January 1, 1996
February 16, 2019