Section 1
Union Secures the Border States
Key Idea
Four slave states—Delaware, Maryland, Kentucky, and Missouri—chose not to secede from the Union. These border states became critical territories that both the North and South wanted to control. President Lincoln knew that keeping them in the Union was essential for the war effort.
Their location provided major strategic advantages. Maryland surrounded the U.S. capital, Washington D.C., and its loss would have been devastating. Kentucky and Missouri controlled key parts of the Ohio and Mississippi Rivers, which were vital transportation routes for troops and supplies.