in U.S. history, policy by which first settlers, or “squatters,” on public lands could purchase the property they had improved. Squatters who settled on and improved unsurveyed land were at risk that when the land was surveyed and put up for auction speculators would capture it. Frontier settlers seldom had much cash, and, because they held no title to their land, they even risked losing their homes and farms to claim jumpers prior to the government auction.

Squatters pressured Congress to allow them to acquire permanent title to their land without bidding at auction. Congress responded by passing a series of temporary preemption laws in the 1830s. Bitterly opposed by Eastern business interests who feared that easy access to land would drain their labour supply, the preemption laws also failed to satisfy the settlers seeking a permanent solution to their problems.

In 1841 Henry Clay (Clay, Henry) devised a compromise by providing squatters the right to buy 160 acres of surveyed public land at a minimum price of $1.25 per acre before the land was sold at auction. Revenues from the preemption sales were to be distributed among the states to finance internal improvements.

The Pre-Emption Act of 1841 remained in effect for 50 years, although its revenue-distribution provision was scrapped in 1842. The law led to a great deal of corruption—nonsettlers acquired great tracts of land illegally—but it also led to the passage of the Homestead Act of 1862 by making preemption an accepted part of U.S. land policy.