<P> In the context of the American Civil War (1861--1865), 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> <P> In Virginia, Kentucky and Missouri, there were both pro-Confederate and pro-Union governments . West Virginia was formed in 1862--63 after unionists from the northwestern counties of Virginia then occupied by the Union Army had set up a loyalist ("restored") state government of Virginia . Lincoln recognized this government and allowed them to divide the state . Though every slave state except South Carolina contributed white battalions to both the Union and Confederate armies (South Carolina Unionists fought in units from other Union states), the split was most severe in these border states . Sometimes men from the same family fought on opposite sides . About 170,000 border state men (including African Americans) fought in the Union Army and 86,000 in the Confederate Army . </P>

What was the dividing line for the civil war