Border states (American Civil War)

In the American Civil War (1861–65), the border states were four, later five, slave states that primarily supported the Union. They were Delaware, Maryland, Kentucky, and Missouri, and after 1863, the new state of West Virginia. To their north they bordered free states of the Union, and all but Delaware bordered slave states of the Confederacy to their south.

Of the 34 U.S. states in 1861, nineteen were free states and fifteen were slave including the four border states; each of the latter held a comparatively low percentage of slaves. Delaware never declared for secession. Maryland was largely prevented from seceding by local unionists and federal troops. Two others, Kentucky and Missouri, saw rival governments, though their territory mostly stayed in Union control. Four others did not declare for secession until after the Battle of Fort Sumter and were briefly considered border states: Arkansas, North Carolina, Tennessee, and Virginia. They are called the Upper South. A new border state was created during the war, West Virginia, which was formed from 50 counties of Virginia and became a new state in the Union in 1863 (with, initially, gradual abolition law).

Kentucky and Missouri had both pro-Confederate and pro-Union governments. West Virginia was formed in 1862–63 after Virginia Unionists from the northwestern counties of the state, then occupied by the Union Army consisting of many newly formed West Virginia regiments, had set up a loyalist "restored" state government of Virginia. Lincoln recognized this government and allowed them to divide the state. Kentucky and Missouri had adopted secession ordinances by their pro-Confederate governments (see Confederate government of Kentucky and Confederate government of Missouri), but the two states were never fully or officially under Confederate control, though at various points Confederate armies did enter those states and controlled certain parts of them.

Besides combat between regular armies, the border region saw large-scale guerrilla warfare and numerous violent raids, feuds, and assassinations. Violence was especially severe in West Virginia, eastern Kentucky, and western Missouri. The single bloodiest episode of guerrilla warfare was the 1863 Lawrence Massacre in Kansas, in which at least 150 civilian men and boys were killed. It was launched in retaliation for an earlier, smaller raid into Missouri by Union men from Kansas.

Lincoln's 1863 Emancipation Proclamation did not apply to the border states, because they were not in rebellion. Of the states that were exempted from the proclamation, Maryland (1864), Missouri, Tennessee (January 1865), and West Virginia (February 1865) abolished slavery before the war ended. However, Delaware  and Kentucky, while they saw a substantial reduction in slavery, did not see the abolition of slavery until December 1865, when the Thirteenth Amendment was ratified.

With geographic, social, political, and economic connections to both the North and South, the border states were critical to the outcome of the war. They are still considered to delineate the cultural border between the North and South. Reconstruction, as directed by Congress, did not apply to the border states because they never seceded. They did undergo their own process of readjustment and political realignment after passage of amendments abolishing slavery and granting citizenship and the right to vote to freedmen. After 1880 most of these jurisdictions were dominated by white Democrats, who passed laws to impose the Jim Crow system of legal segregation and second-class citizenship for blacks. However, in contrast to the Confederate States, where almost all blacks were disenfranchised during the first half to two-thirds of the twentieth century, for varying reasons blacks remained enfranchised in the border states despite movements for disfranchisement during the 1900s.