Question

which of the following factors best explains the territorial expansion of slavery in the middle of the nineteenth century? A. The belief in Manifest Destiny encouraged settlers to move to the West.B.The Mexican-American War incorporated extensive new lands into the United States.C.The rise of industry in the North created more demand for raw materials such as cotton.D.The growing nativist movement sought to place restrictions on new immigrants.

Answer 1

B. The Mexican-American War incorporated extensive new lands into the United States.

Step-by-step explanation:

B. The Mexican-American War incorporated extensive new lands into the United States. This is the best explanation for the territorial expansion of slavery in the middle of the nineteenth century because the Mexican-American War resulted in the United States gaining control over large areas of land in the Southwest, including California, Arizona, New Mexico, and parts of Texas. This opened up new opportunities for the expansion of the slave economy, as these areas were not yet part of the United States when slavery was abolished in the North.