A revolution removes Spanish rule in Mexico and establishes a republic.
Jedediah Smith crossed the Great Basin and Sierra Nevada
Marcus and Narcissa Whitman found a mission at Walla Walla.
The government-sponsored expedition led by John Fremont sets off.
John O'Sullivan writes inspirational editorial on manifest destiny.
Joseph Smith is killed by a mob in Illinois, and Brigham Young takes over as leader of the Mormons.
The Donner Party gets lost in the Sierra Nevada and resorts to cannibalism to prevent starvation in the snow.
Brigham Young leads the Mormons westward, but stops at the Great Salt Lake and founds New Zion.
The Whitmans are killed by Native Americans in response to a measles epidemic.
Keeps the Indians away from major trails. (at least on paper...)