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. Two slave states never declared a secession or adopted an ordinance: Delaware and Maryland.
