Between 1803 and 1848, the United States expanded her borders by more than two million square miles. These acquisitions in the trans-Mississippi West more than tripled the size of our country and would eventually become familiar to Americans as the states of Nebraska, Kansas, North Dakota, South Dakota, Oklahoma, Texas, New Mexico, Colorado, Wyoming, Montana, Idaho, Utah, Arizona, California, Nevada, Washington and Oregon.

President Thomas Jefferson began this expansion with the Louisiana Purchase. Soon after, he sent the Corps of Discovery, commonly known now as the Lewis and Clark Expedition, west to see what he had bought. It took Lewis and Clark two years to get to the Pacific Coast and home again but they returned with stories that fired the imagination of their fellow countrymen. The great Columbia River abounded with salmon, the natives were friendly, and there was a long valley more fertile than anywhere else on earth. The lands were lush, the rainfall plentiful, the winters mild. It was the "land of milk and honey." If only settlers could get there, the United States might be able to beat out the English and truly expand their borders "from sea to shining sea."

But the route that Lewis and Clark had followed – up the Missouri River, across the Rocky Mountains, down the Snake to the Columbia River – proved impractical for routine travel. Nonetheless, the journey by Lewis and Clark had convinced American entrepreneurs that there were fortunes to be made in the beaver trade out west and it did not take long until they sought a route to their riches.

John Jacob Astor was the first to seize upon the possibilities. He decided to try two methods of conquering the country. First, he would send a ship, the Tonquin, around the tip of South America and up the coast to the mouth of the Columbia. In addition, he dispatched Wilson Price Hunt and his "Astorians" overland. The Tonquin was destroyed but Hunt and the Astorians made it to the mouth of the Columbia where they founded the town of Astoria which still thrives on the Oregon-Washington border.

In 1812, one of the Astorians, Robert Stuart, headed east from the Pacific coast to inform his employer that the Tonquin had been lost. Stuart, concerned about encounters with the fierce Blackfeet, decided to take a more southernly route and, in doing so, he "discovered," in reverse, the Oregon Trail.