umm..... becuase they mabe just didnt wanted to they wanted to protect thier farms some of them had to go by force. good question.
They were not in favor of succeeding
The exact number of the Federal naval officers that decided to join the Confederacy is not known.
11
border states
The Northern slave-states of Kentucky and Missouri.
Kentucky was a slave holding state that did not join the confederacy. Lincoln is quoted as having said something to the effect that if he could not win Kentucky he could not win the war. Also, once Lincoln issued the immacipation proclimation, only slaves within states that had joined the confederacy were free, meaning that Kentucky could still legally continue to own slaves.
Missouri, Kentucky, West Virginia, Maryland and Delaware
Three states, Kentucky, Maryland, and Missouri were slave holding states but did not join the Confederacy. Each of these states have complex reasons for remaining in the Union and yet retained their slaves. Tennessee was a slave state and joined the Confederacy. The latter was late, joining the South in May of 1861.
The Confederate leaders wanted as many states as possible to join them. Whether non-slave states could join was moot, since all of the non-slave states were in favor of preserving the Union.
compromise of 1820
In the terms of the 1860's the "border states" were slave holding states that did not join the Confederacy but were allowed to retain their slaves. Geographically, Kentucky and Missouri were a buffer of sorts between the South and the North. Maryland surrounded the city of Washington DC making it necessary to prevent it from joining the Confederacy. Delaware's location and very small slave population were not important.
Eleven Southern states eventually joined the Confederacy and these fought in the US Civil War. Other slave holding states such as Missouri, Kentucky, Maryland and Delaware were part of the Union during the war. Slave owners in the former three states may have wished to join the South, however, they were a minority group of people.