John Disturnell (1801-1877). Engraved map with original hand-color in full. New York: J. Disturnell, 1847. 31 x 42 1/2 inches. One of the most important maps in American history: the map used by the U.S. and Mexican governments to negotiate the Treaty of Guadalupe-Hidalgo. The nineteenth century saw a burgeoning of America’s cities as settlers travelled West in search of a new beginning. With this migration came a tremendous demand for guide books, directories, surveys and maps. New York and Philadelphia became leading centers of publishing, and at the forefront of the industry was John Disturnell. Ever the opportunist, Disturnell recognized that maps of Texas and the West would become popular items after the state was admitted to the United States in 1845. His popular and widely distributed map of Mexico essentially followed White, Gallagher & White’s 1828 map, itself based on Henry Tanner’s landmark 1826 map. Tanner’s map had greatly improved upon previous cartographic efforts in the region in numerous regards. However, his most significant action was to redraw New Mexico’s southern border eight miles further north at the western end and eighty miles further north in the east. Disturnell retained this significant amendment in his map and, thus, when the U.S. Government under President Filmore selected Disturnell’s map for negotiating a new border after the Mexican-American War, Tanner’s revised boundary passed into law.Both Spanish and English versions of the map were included as official documents in the 1848 Treaty of Guadalupe-Hidalgo. In all, twenty-four editions of this map were produced with amendments made to each edition. Seven editions alone were published in 1847. The seventh edition was attached to the United States’ copy of the Treaty, while the Mexican version of the Treaty bore a copy of this, the twelfth edition. Indeed, the twelfth edition is preserved in the archives of the Government of Mexico and certified in both Spanish and English. The English certificate reads: “This is the Map, referred to in the Fifth Article of the Treaty of Peace, Friendship, Limits and Settlement, between the United States of America and the Mexican Republic, signed this day. Witness our hands and seals, at Guadalupe Hidalgo, this second day of February, one thousand eight hundred and forty-eight.”Disturnell’s large and detailed map depicts all of Mexico, the entire western part of North America beyond the Mississippi River and below the 42nd parallel, as well as all of Florida and Texas. Insets provide views of Vera Cruz and Alvarado, as well as statistical and distance tables. However, on Disturnell’s map the province of New Mexico is narrower and ran farther north than it does today. Texas is shown with its approximate present boundaries although its panhandle stretches as far north as the Arkansas River and the western flank of Texas extends to the Rio Grande with Santa Fe in Texas. What is presently California, Nevada, most of Utah and Arizona is marked Alta California, while the land below the Gila River is recorded as the state of Sonora.