The march across the frontier was fueled by the 640 free acres that each adult white male could claim in the mid-1840s. The westward expansion that Americans regarded as their “manifest destiny” seemed a ready solution to the problems of the 1830s, when the country was in a deep depression, with land panics, droughts, and an unstable currency. Despite ignorance of western geography and the hardships it held, the Oregon Trail, a 2,000-mile frontier thoroughfare, was viewed with covetous eyes, especially in increasingly populous Missouri. Around Independence, Missouri, the trees thinned, the settlements ended, and the Oregon Trail began.

More than 53,000 people traversed the trail between 1840 and 1850 en route to western Oregon. In 1850, the Donation Land Act cut in half the allotted free acreage, reflecting the diminishing availability of real estate. But although a single pioneer man was now entitled to only 320 acres, and single women were excluded from land ownership, as part of a couple they could claim an additional 320 free acres. This promoted marriage and, in turn, families on the western frontier, and helped to fulfill Secretary of State John C. Calhoun’s prediction that American families could outbreed the Hudson’s Bay Company’s bachelor trappers, thus winning the battle of the West in the bedroom.

The Donation Land Act also stipulated that nonwhites could not own any part of the Oregon Territory, enabling the pioneers to seize native people’s lands with impunity. The act impeded the growth of towns and industries too, as large parcels of land were given away to relatively small numbers of people, which kept the population geographically distant from one another. This was one reason why urbanization was slow in coming to the Northwest.