The "Border States" were slave states.
border states
Weat Virginia Delaware, Maryland, Missouri, and Kentucky were five slave states that did not secede the Union, and the were were called border states.
There were five slave states that remained in the Union. Initially there were four -- Delaware, Maryland, Kentucky and Missouri. West Virgina separated from Virginia when it (Virginia) seceded from the Union. West Virginia was admitted to the Union in 1863 as a slave state. West Virgina remained in the Union making it the fifth slave state not to secede. These five slave states were called border states.
At the beginning of the US Civil War, the "southern" border States were Kentucky and Missouri. In this answer, Maryland is excluded in that although it was a pro=southern slave State, it cannot be considered a border State.
The "Border States" were slave states.
The Mississippi River.
The Ohio
None of the Border States seceded even though they were slave states.
Slave states. Some border states made attempts to secede, but for one reason or another, failed to do so.
It was the southern border of Missouri and was just south of the point where the Ohio River ends.
The Missouri River
The Missouri River
The Missouri River
Border states or Buffer states.
border states
During the Civil War, border states were slave states that had not succeeded from the Union. The four border states were Delaware, Kentucky, Maryland, and Missouri.