The Oregon and California Trails: The Great Migration

The overland rush to Oregon and California, sometimes called the Great Migration, has little parallel in American history. Between eighteen forty-one and eighteen sixty-nine, when the transcontinental railroad made wagon travel obsolete, somewhere between three hundred thousand and five hundred thousand people crossed the North American continent on foot, on horseback, and in wagons. Most of them entered what is now Kansas at the Missouri border and walked west.

The Oregon and California Trails ran together across northern Kansas, following the Kansas River and then the Little Blue River toward the Platte in Nebraska. The jumping-off towns were just over the Missouri border: Independence, Westport, and Saint Joseph. Emigrants gathered there in April and May, waiting for the prairie grass to grow tall enough to feed their livestock before starting out. Timing mattered. Leave too early and the animals starved. Leave too late and the Sierra Nevada passes closed with snow.

Supplies mattered, because once the wagons left the settlements there were few places to replace a broken axle or buy provisions.

The journey across Kansas took roughly three weeks. Emigrants wrote in their diaries about the scale of the grass, which could stand chest-high in wet years, about the creeks that cut unexpected ravines across the route, and about the columns of other wagons visible for miles in every direction, the entire migration strung out in a moving line that one diarist compared to a small city on wheels.

What they crossed was the western edge of Kansa and Pawnee territory. The traffic, hundreds of thousands of people and their livestock over three decades, stripped the grass from the trail corridor, drove away the bison, and introduced diseases that traveled faster than the wagon trains themselves. The Oregon Trail was not merely a route of settler migration. It was the instrument by which the central plains were transformed.