What issue was addressed by the Missouri Compromise?

exploration

western expansion

Native American rights

slavery

The issue addressed by the Missouri Compromise was: Slavery.

Missouri requested to enter in the Union as a slave state, which threatened to upset the balance between slave states and free states. The Congress solution was to grant Missouri's request but also admiting Maine as a free state. This kept the balance. So afterwards the United States contained twenty-four states, evenly divided.

Before the Missouri Compromise of 1820, there was tension between anti-slavery and pro-slavery circles within the U. S Congress. It got intense after Missouri wanted to join a slave state, this caused some problem because it was going to affect the balance within the country. At that time, there existed twenty two states in the country, eleven slave states, and eleven free states.

To balance the equation and for peace to reign, Congress composed a two-part compromise, granting Missouri's offer but also enabling Maine as a free state.

So basically the Missouri Compromise was centered around slavery, and slavery expansion.