<span>Prior to the Mexican American war president Polk sent John Slidell to Mexico to negotiate an agreement between that the Rio Grande River would be the southern border of Texas. ... The United States annexed the territory of California in 1848 following its victory in the Mexican-American War.</span>
Answer:
European encounters with Africa had occurred for hundreds of years. It affected the Africans so some were brought into slavery.
Explanation:
So States were disappearing. And new States joined the slave trade and became wealthy and powerful.
the word is Media Saeculorum
