In the terms of the 1860's the "border states" were slave holding states that did not join the Confederacy but were allowed to retain their slaves. Geographically, Kentucky and Missouri were a buffer of sorts between the South and the North. Maryland surrounded the city of Washington DC making it necessary to prevent it from joining the Confederacy. Delaware's location and very small slave population were not important.
The US Civil War.
With regards to the US Civil War, many historians prefer to use the term of The War Between the States. For some historians, what is generally called the US Civil War, is not an accurate use of the term "civil war".
The American Civil War or The War Between the States.
Well, if you want to count US vs. US, there was the Civil War.
Technically, four so-called border States were neutral in the US Civil War. They were Missouri, Kentucky, Maryland and Delaware.
*The civil war *The War between the States
The northern states in the US Civil War called themselves "The Union."
There is no chance that there will ever be a civil war in the United States.
The United States of America fought the Confederate States of America in the Civil war.
There were 34 states when the US Civil War began.
The War Between the States is another name for the US Civil War.
The War Between the States.
The US Civil War was also known as the War Between the States.
There are no 'civil wars' in any US States; we have not had a civil war since 1865.
Kansas, Nevada and West Virginia became states during the US Civil War.
Prior to the US Civil War, Southern states were sometimes referred to as slave holding states. Technically and in reality, until the Civil War, all US states were called US states. This is not some way to marginalize the antebellum period of the US.
The US Civil War.