For much of the middle portion of the 19th century, Manifest Destiny – the idea that the United States was destined to occupy and remake the land between the Atlantic and Pacific Oceans – shaped American foreign policy. While the Louisiana Purchase and the 1846 Oregon Treaty furthered the goal of coast-to-coast settlement, the February 2, 1848 signing of the Treaty of Guadalupe Hidalgo completed the southern half of the Manifest Destiny puzzle and ended the Mexican American War.
While the Treaty of Guadalupe Hidalgo resolved the issues between Mexico and the United States that led to war, it created many new issues within the United States as rival political factions vied to form the new territory in their own view.
By virtue of Nicholas Trist’s execution of the Treaty of Guadalupe Hidalgo and the United States’ Senate’s forthcoming ratification of the agreement, the United States added over 500,000 square miles of territory to its borders. While this area was substantial, it paled in comparison to the 828,000 square miles of territory gained via the Louisiana Purchase.
Nevertheless, in light of the developing tensions that contributed to the American Civil War, the organization of the new territory presented a serious political challenge. Demonstrative of such tension is the Wilmot Proviso which sought to prevent the spreading of slavery into lands gained during the Mexican American War. Despite the political issues of the day, the territory gained through the Treaty of Guadalupe Hidalgo would be carved into portions of ten different states.
President James Polk was not silent during the debate of how to carve up the territory acquired via the Treaty of Guadalupe Hidalgo. In December, 1848, he delivered a message to Congress outlining how he believed the new lands should be organized. Illustrating a very different view of the American West, President Polk’s map is illustrative of just one of many competing viewpoints.
Given the eventual organization of this territory into ten states, Polk’s map presents an interesting idea of how the American West could have been shaped very different than the familiar lines of the actual western states.