Ill Give Brainliest!

This agreement allowed Missouri to enter the United States as a slave state and Maine as a free state; slavery would also be prohibited north of Missouri's southern border?

a. The Adams-Onis Treaty

b. The Missouri Compromise

c. The Northwest Ordinance

d. The Main Deal

b. The Missouri Compromise

Explanation:

The purpose of the Missouri Compromise was to keep a balance between the number of slave states and the number of free states in the Union. It allowed Missouri to enter as a slave state at the same time Maine entered as a free state, thus maintaining a balance in numbers of free and slave states.

b.

Explanation:

The Missouri Compromise was the legislation that provided for the admission of Maine to the United States as a free state along with Missouri as a slave state, thus maintaining the balance of power between North and South in the United States Senate.