The economic system of these states, located in the southern region in the US, this relied heavily on availability of the slave labor of African-Americans in agriculture and plantations. Also, the main reason why the confederacy was created was in response to the threat to the institution of slavery that represented the election of Abraham Lincoln as President of the US. It wasn't until after the beginning of the American Civil War, in 1861, that the other four slave states joined such as Arkansas, Tennessee, North Carolina and Virginia.
