The popularity of the trail increased as "Oregon Fever" took hold in areas adjacent to the Mississippi River in the early 1840s. By the middle of the decade, thousands of migrants flocked to Oregon, which the United States eventually secured by treaty with Great Britain in 1846.
The trail was written about by the American historian Francis Parkman, who published The Oregon Trail in 1849. Parkman's book, a first-person account of his experiences on the trail, is considered a classic of American history.

