The border states were crucial to the outcome of the US Civil War. The border states in this answer were Missouri, Kentucky, Maryland and Delaware. Here is a summary of why these states were so important:
A. The above mentioned border States did not secede from the Union at the onset of the war when Fort Sumter was attacked;
B. If 3 of the 4, namely Missouri, Kentucky, and Maryland had joined the Confederacy, the so-called "white" population of the South would have increased by 45%, thus creating a larger pool of men to serve as soldiers;
C. Also, the industrial base of the Confederacy would have increased been increased by 80%; and
D. The succession of Maryland would most likely have caused the Union to abandon Washington DC as Virginia and Maryland would have the US capital surrounded.
Maryland was an important border state because it surounded DC. If Maryland seeced DC would be surounded by southern states and Lincoln would have no chance.
The Border States were a key part of the US Civil War. They were slave states that did not join the Confederacy, it was important for the Union to prevent that they did not secede and join the South.
Because these four important states could have tilted the war in favour of whoever they supported. In the end, it was the North.
Twenty-five states made up the Union during the civil war. These include five slaves states that were referred to as border states. Nevada and West Virginian became states during the Civil War and joined with the Union states.
Technically, four so-called border States were neutral in the US Civil War. They were Missouri, Kentucky, Maryland and Delaware.
Kentucky
What were 5 border states during the civil war
There were 430,929 slaves in the Border States.
They were border states for the Union and Confederate. Maryland was especially important because it contained the U.S. capital (Washington D.C.)
The three border states during the US Civil War were Missouri, Kentucky and Maryland. The were slave states but did not join the Confederacy. Delaware also had slaves and was not "on the border" between the North and the South
During the Civil War, border states were slave states that had not succeeded from the Union. The four border states were Delaware, Kentucky, Maryland, and Missouri.
The Union did not want to lose anymore of the territory.
Maryland, Delaware, Kentucky, Missouri
During the American Civil War there were five states which stayed neutral and were given the name "border" states. They were called border states because they each bordered a free state and were aligned with the union. The five border states were Delaware, Kentucky, Maryland, Missouri, and West Virginia.
Maryland was an important border state because it surounded DC. If Maryland seeced DC would be surounded by southern states and Lincoln would have no chance.
Maryland
The Border States, or the Buffer States.