Answer:
The agreement in which Congress agreed to allow two states into the Union, one free and one slave, and established slavery policies in the Louisiana Territory was the Missouri Compromise.
Explanation:
The Missouri Compromise was an agreement reached in 1820 between members of the Congress, according to which the state of Missouri was admitted to the Union as a slave state, and the state of Maine as free from slavery.
As a result of the Missouri Compromise, the area of slavery expanded: slavery was prohibited only north of the 36 ° 30 ’ parallel and west of the Mississippi.
