The United States includes Oregon and California because of South Pass!!!
South Pass!!!

South Pass is located in Wyoming. It is one of the most important landmarks on the Oregon Trail. With out South Pass traveling across the country would have been impossible. There is a huge possibility that Oregon and California would not have been part of the United States. It was founded by a man named Robert Stuart in 1812. South Pass has a 7,550 ft elevation, and it is the key to westward migration. South Pass is 35 miles long. If you left from Independence, Missouri, it would take you about 3 months to get to South pass. It is the half way mark to Oregon. South Pass is a mountain pass on the on the Continual Divide in the Rocky Mountains. The Pass is a natural gap in the Rockies that is 12 miles wide. It is actually pretty flat prairie land. The Sweetwater River rises on the east side of the Pass and flows into the Atlantic Ocean while the Pacific Creek rises on the west side and flows to the Pacific. Hallie B.