Acquisition of Oregon and California 


Ned Eddins

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Oregon Territory              Treaty of Guadalupe Hidalgo

Manifest Destiny        Geographical Center        Territorial Expansion

World history centers around one people taking another peoples land…seldom, if ever, by peaceful means. At various times, Spain, Russia, England, and the United States claimed the land west of the Continental Divide and east of the Pacific Coast. The only people with a real claim on the land were the American Indians.

Why didn’t Indians have any claims in the land negotiations? The reason is:

In 1452, the Catholic Pope Nicholas V issued to King Alfonso V of Portugal a proclamation declaring war against all non-Christians throughout the world, and specifically sanctioning and promoting the conquest, colonization, and exploitation of non-Christian nations and their territories. This “Doctrine of Discovery” gave Christian countries the rights to the lands of non-Christians.

In 1823, the United States Supreme Court decided in the Johnson v. McIntosh decision that:

 “as a result of European discovery, the Native Americans had a right to occupancy and possession.” But “tribal rights to complete sovereignty were necessarily diminished. The principle discovery gave exclusive title to those who made it.”

Chief Justice John Marshall observed:

…that European nations had assumed “ultimate dominion” over the lands of America during the Age of Discovery, and that upon “discovery” the Indians lost “their rights to complete sovereignty, as independent nations,” and retained only a right of “occupancy” in their lands”

The Doctrine of Discovery was used to move the Five Civilized Tribes: Cherokee, Creek, Seminole, Choctaw, and Chickasaw, as well as a great many other Indian tribes to the Oklahoma Territory. This law is still on the books of the United States Legal system.

Acquisition of the Oregon Country:

The Oregon country extended from the Oregon-California border to the base of Russian Alaska. After the War of 1812, Great Britain offered to relinquish its claims to the Oregon Country south of the Columbia River, but the United States refused. The crown jewel of the Northwest was Puget Sound. It was the only deep sea port north of Mexican California, and the United States wanted Puget Sound. Unable to settle the boundary dispute, an agreement of joint occupancy was signed at the Oregon Convention in 1816. Renewable at ten-year periods, this agreement lasted until 1846.

Oregon Treaty of 1846 determined the border between the United States and Canada at the forty-ninth parallel. It was stipulated all of Vancouver Island would be part of Canada. Under the Oregon Treaty, the future states of Washington, Oregon, Idaho, and part of Montana were in the United States.

Acquisition of California Territories:

Two years later, February 2, 1848, the Mexican and United States governments signed the Treaty of Guadalupe Hidalgo. Here is an interesting side note that few people are aware of:

 Despite winning the Mexican War, the American government paid the Mexican government fifteen million dollars and assumed debts of three million two hundred and fifty thousand dollars. The total cost of the Mexican Government cession to the United States was eighteen million two hundred and fifty thousand dollars…three million two hundred and fifty thousand dollars more than the United States paid for the Louisiana Territory.

The settlement of the Oregon Country boundary and the signing of the Treaty of Guadalupe Hidalgo  basically completed the geographical outline of the United States. Six future western states… Washington, Idaho, Oregon, California, Nevada, Utah…and parts of five other future states… Colorado, Wyoming, Montana, New Mexico, and Arizona…were under the American flag. The Guadalupe Hidalgo treaty also stipulated Mexico give up any claims to Texas.

On May 14, 1836, the Treaty of Velasco between Texas and Santa Anna declared an end to the war with the Mexican army retreating south of the Rio Grande. The Mexican government never ratified the Treaty of Velasco. Skirmishes over the Texas border continued between Mexican and American outposts. Mexico claimed the Pecos River formed the boundary…Texans claimed the Rio Grande.

OC-Territorial Expansions
American Western Expansion

The Guadalupe Hidalgo treaty increased the size of the United States by about one-third (this includes relinquishing any claims to Texas)–an addition greater than  the Louisiana Purchase. Few Americans even know the name of the President who brought the most land under the American Flag…President James K. Polk. Territories acquired during his administration determined, except the base of Arizona, the outline of the United States.

Territorial Expansion:

The mountain man’s search for beaver pelts was an underlying factor in determining the geographical outline of the United States. Three great river systems…the Missouri, the Snake, and the Colorado…drained the major fur trade area of the Rocky Mountains. The territories drained by these rivers had a direct bearing on the territorial expansion of the United States.

OC-River Systems
The United States River System

The Missouri River and its tributaries established the upper Louisiana Territory as being below the forty-ninth parallel. Settlement of the Oregon Territory boundary in 1846, gave the United States the watershed of the lower Columbia and the Snake rivers. With the exception of California, a major portion of the Mexican cession was in the valleys and tributaries of the Colorado and Green rivers.

Geographical Center of Fur Trade:

The largest tributary of the Colorado, Columbia, and Missouri rivers head within a sixty-eight mile radius of the Grand Teton peak on the western Wyoming border. Another circle with a radius of one hundred and ninety-one miles covers all of the Rocky Mountain Rendezvous sites and the Three Forks area of Montana. With the Grand Teton as the geographical center, this area covers the richest beaver country in the Rocky Mountains.

Geological Center of the Fur Trade

The end of the Mountain Man Indian fur trade rendezvous in 1840 was the beginning of a new way of life for many Americans–some good, some bad.

Manifest Destiny:

At the end of the 1840 rendezvous, the first non-missionary family went to the Oregon Country. Joel Walker and his family were the first settlers to travel over what would become the Oregon Trail. Joel was the brother of Joseph Rutherford Walker. Manifest Destiny had started for hundreds of thousands of American pioneers traveling the Oregon, Mormon, and California trails.

OT-Oregon Mormon Trail
Oregon – California – Mormon Trails

America’s Manifest Destiny was the beginning of the end for several hundred thousand Native Americans and millions of buffalo.

Forty-six years after the first immigrant family (Joel Walker’s) traveled over the Oregon Trail, the last buffalo hunt was held in the Judith Valley, and the vast majority of free-roaming Plains Indians were confined to reservations–a way of life gone forever.

Manifest Destiny was a “catch-phrase” to justify the United States territorial expansion to the Pacific Ocean. The phrase Manifest Destiny was coined in 1844 by New York journalist John L. O’Sullivan in his magazine the Democratic Review. One of the most misunderstood phrases on the Internet, Manifest Destiny expresses the belief that the United States was divinely inspired to spread democracy and freedom across North America.

The Oregon Country article was written by  Ned Eddins of Afton, Wyoming.

Permission is given for material from this site to be used for school research papers.

Citation: Eddins, Ned. (article name) Afton, Wyoming. 2002.

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