<P> In the context of the American Civil War (1861--65), the border states were slave states that did not declare a secession from the Union and did not join the Confederacy . To their north they bordered free states of the Union and to their south they bordered Confederate slave states . Of the 34 U.S. states in 1861, nineteen were free states and fifteen were slave states . Four slave states never declared a secession: Delaware, Kentucky, Maryland, and Missouri . Four others did not declare secession until after the Battle of Fort Sumter and were briefly considered to be border states: Arkansas, North Carolina, Tennessee, and Virginia--after this, they were less frequently called "border states". Also included as a border state during the war is West Virginia, which was formed from 50 counties of Virginia and became a new state in the Union in 1863 . </P> <P> In the border states there was widespread concern with military coercion of the Confederacy . Many if not a majority were definitely opposed to it . When Abraham Lincoln called for troops to march south to recapture Fort Sumter and other national possessions, southern Unionists were dismayed . Secessionists in Arkansas, North Carolina, Tennessee, and Virginia were successful in getting those states to declare their secession from the U.S. and to join the Confederate States of America . </P>

What was a slave state that remained in the union called