In the early 1840s, a large increase in the migration of American settlers west of the Mississippi River was sparked by

A) the abolition of slavery in the Deep South.
B) Indian tribes regaining land east of the Mississippi River.
C) the economic depression that began in 1837.
D) a widespread rejection of the concept of manifest destiny.
E) Mexico's sale of California to the United States in 1840.

Manifest Destiny

Phrase first used in 1845 to urge annexation of Texas; used thereafter to encourage American settlement of European colonial and Indian lands in the Great Plains and the West and, more generally, as a justification for American empire.

Economic Depression

A severe and prolonged downturn in economic activity characterized by significant decline in GDP, high unemployment, low spending, and deflation.

Mississippi River

One of the longest rivers in North America, flowing from northern Minnesota to the Gulf of Mexico, and historically significant as a major transport route for trade, especially during the 19th century.