About 3 million
The war was pushed by pro-slave interests (Polk himself was a pro-slave southerner), renewing the slave question; after the war with Mexico, this conflict planted the seeds of the American Civil War (1861-1865).
The American Civil War.
15 slave states and 19 free states during the American Civil War
To keep a lengthy answer short, Slavery. That and the power of slave states in comparison to the power of non slave states in government.
African Americans struggled against the slave system because the system denied them both freedom and wages
The civil war was fought because of slavery. North=No Slavery South=More Slavery
No, it was a slave-state that had narrowly voted against joining the Confederacy.
People that would buy a slave would buy them because they needed work to be done. They were called, "slave owners". Slavery is now illegal. The Civil War fought against slavery.
It divided them between pro-slave and anti-slave believers. It eventually led to the American Civil War (1861-1865)
Delaware, Kentucky, Maryland, and Missouri were four slave states that did not secede from the Union. West Virginia, another slave state, seceded from Virginia and joined the Union during the Civil War. it was 4 that didn't secede from the union.
The North. And Congress was increasingly reluctant to allow new slave-states. So the voting balance in Congress was tilting against the South. That's what they were so defensive about.