A map of the western United States published during the Mexican-American War, just before the California Gold Rush. California is still part of Mexico at this time.

This fascinating map divides the American west into two enormous regions: Oregon and Upper California. At the time of publication in 1847, California was still a year away from being annexed by the United States after the Mexican American War (1846-8). The boundary dispute over the border between British Canada and the Oregon Territory had also just been resolved with the ratification of the Oregon Treaty in 1846.

Within a decade of the printing of this map, later editions would show the annexation of California by the US, the start of the Gold Rush, the appearance of the New Mexico and Utah Territories, and California statehood. The settlement of Nueva Helvetia, located on the site of modern-day Sacramento, is the only town marked in the interior of California. Short paragraphs of text describe the region between the Great Salt Lake in Utah and the Rocky Mountains, known at the time as the unexplored Great Interior Basin of California.

Bright original hand-colour. [USA10063]