The main compromise that tried to “solve” the debate between free and slave states was the Missouri Compromise of 1820.

Quick Scoop

  • It admitted Missouri as a slave state and Maine as a free state , keeping the number of free and slave states balanced in the Senate.
  • It drew an imaginary line at 36°30′ latitude across the Louisiana Territory:
    • North of the line: slavery was banned (except in Missouri).
* **South** of the line: slavery was allowed.
  • This deal temporarily eased tensions between North and South and kept political peace for several decades, but it did not truly resolve the conflict over slavery.

Why it mattered

  • It gave both sides something:
    • Slaveholders got Missouri and the chance for slavery south of 36°30′.
* Anti-slavery Northerners got Maine and a large region where slavery was barred.
  • It became the standard way Congress tried to manage slavery in new territories: balance a slave state with a free state and use geography to divide where slavery could spread.
  • Later events, especially the Kansas–Nebraska Act of 1854 , repealed this arrangement and reopened the conflict, helping lead to the Civil War.

Related compromise you might also see

Sometimes textbooks or teachers also mention the Compromise of 1850 as another big attempt to balance free and slave interests:

  • Admitted California as a free state.
  • Let Utah and New Mexico decide slavery by popular sovereignty (voters in the territory decide).
  • Ended the slave trade (but not slavery) in Washington, D.C., and passed a tougher Fugitive Slave Act.

But if your question is asking “what compromise solved the debate between free & slave states?” for a U.S. history test or worksheet, the expected answer is almost always:

The Missouri Compromise of 1820.