1820 Warner Pocket Map of the United States

An uncommon 1820 map of the United States by Benjamin Warner. Following on John Melish's wall map of 1819, this is one of the earliest maps to depict the United States extending from the Atlantic to the Pacific. As Wheat notes, this map is significant as one of several issued up to about 1823 that galvanized geographic ideas regarding the only tenuously explored lands beyond the Rocky Mountains, including the mythical 'River of the West' or 'Buenaventura' and other speculations.

The United States after the Adams-Onís Treaty

Following the 1819 Adams-Onís Treaty (on the map identified as the Florida Treaty), this map is among the earliest to include Florida as part of the United States. The treaty also established the Mexican-American border, shown here extending from the Pacific at 42° North along the Arkansas River to 100° West, then along the Red River to the Sabin River and the Gulf of Mexico. The lands to the north of this division, collectively identified as the Missouri Territory, are well mapped for the period, giving evidence to the work of Lewis and Clark with numerous references to their voyages present throughout - including the point 3,000 miles from the Mississippi where expedition's canoes could no longer proceed. The Arkansas Territory, also established as an indirect result of the Adams-Onís Treaty, is illustrated at its ephemeral fullest, extending westward as far as the Mexico (Texas) border. The territorial capital is identified simply as 'Post' (Arkansas Post). Little Rock, further up the Arkansas River, was not founded until 1821.

Perhaps the map's most compelling geography lies in the Mexican territory that would eventually become California, Utah, Nevada, Arizona, and New Mexico. Stretching westward from the Rocky Mountains to the Pacific, this region had been only occasionally penetrated and was, as the map suggests, 'Unexplored Country.' The Great Salt Lake appears in embryonic form, with only its northwestern borders mapped. It is labeled Valle Salado, a term translating to 'Salt Valley' dating to the 1776 Escalante Expedition. The apocryphal Buenaventura River is illustrated, passing from San Francisco Bay easily through the California Coastal Ranges and terminating suggestively close to the Great Salt Lake before continuing again from the top of the lake and heading northwest into the Rocky Mountains. Of the Sierra Nevada range there is no suggestion. There is good detail for the period in Texas, much of which is drawn from Humboldt and Pike. The delineation of the Rio Del Norte / Rio Bravo, or as it is now known, the Rio Grande, is exceptionally bold.

Publication History and Census

This map was created and published by Benjamin Warner in 1820. There is only one state but several editions, including one issued for William Guthrie's Geography. The present original color example was separately issued as a folding pocket map on onionskin-style paper. We note a single example in OCLC, part of the collection at the University of Michigan.