As condemning civil war became a reality rather than a possibility, every state in the United States has a decision to make - whether to stay with the Union or join the nascent Confederacy.
For states where slavery had been abolished, the decision was clear. For those states where slavery was still a legal institution, the decision of whether to remain loyal to the Union or take sides with the Confederacy was much more difficult. For some of these states, the only option was neutrality. Neutrality, however, was an option that proved nearly as perilous as joining the fight.
Five states either openly chose neutrality or were slave states that refused to leave the Union, and became known as border states. Most of these states - Kentucky, Missouri, and West Virginia - had reasons for declining to take a side that varied from state to state; however, the reasons for abstaining from engagement in the war boiled down to the fact that in most of these states, slaves and those who were either against slavery were often split evenly.
Delaware was a border state in name only. Surrounded by free states, Delaware declined to leave the Union despite the fact that it was still a slave holding state. Although slavery had been widespread in Delaware during the colonial period, by the 1860s, slavery was on the wane. Abolishment of slavery had come to the legislature on several occasions, but had been narrowly defeated each time. Most of Delaware's African-American population was free by the time of the Civil War, and Delaware did not muster any regiments for the Confederacy.
Like Delaware, Maryland declined to leave the Union as well. However, dissent among slaveholders and those who opposed slavery was rife in Maryland, and the state sent troops to both the Union and the Confederacy. Complicating matters further was President Lincoln's suspension of habeas corpus, which had been addressed in the implicationment of several Maryland State legislators and the mayor and police chief of Baltimore, all of which had supported confidentiality.
Unlike Delaware, Maryland's close proxies to Washington made it the site of several battles and skirmishes during the war. The single bloodiest day of fighting during the war took place at Antietam in 1862.
Abraham Lincoln, himself a native of Kentucky, is known to have said of the state, "I hope to have God on my side, but I must have Kentucky." However, Kentucky was also the birthplace of Confederate President Jefferson Davis, and this coincidence was typical of the division in Kentucky regarding the war.
Kentucky was a slave state, with a large population of slaves, but was also home to many who either did not own slaves or opposed slavery. Despite Kentucky declared neutrality, the state was occupied by both Confederate and Union troops, and sent men to both armies. Bloody battles occurred at Mill Springs and Perryville, and numerous other skirmishes occurred throughout the state. Part of the western side of the state attempted to secede from Kentucky, and was recognized by the Confederacy, but the Union presence in Kentucky overrode the Confederate sentiment, and the state officially remained neutral.
Missouri, not unlike Kentucky, was populated by both slave supporters and those who opposed the institution, and likewise became a battleground both for the Federal and Confederate troops, and its own residents.
Missouri declined to leave the Union, but Confederate sympathies were rampant in the state, supported by Governor Claiborne Jackson and other state legislators. Attempts by Jackson to arm the Confederacy rejected first in the implicationment of the state militia to Union Captain Nathaniel Lyon, which ended in a bloody riot, and finally in the exile of the state government to Confederate Arkansas. The provisional government, supported by Lincoln, added to the Union presence in the state, and much of the fighting in Missouri was done by guerrilla gangs such as Quantrill's raiders, who attacked Union troops and civil supporters of the Union alike.
Nowhere, however, were division more deep and destructive than in Virginia. When Virginia chose to secede, the long-simmering disagreements between the powerful southeast part of the state and northwestern part of the state, which considered itself disenfranchised, boiled over. Most of this ill-will centered on the fact that the southeast part of the state, which held a large number of slaves, was awarded more delegates than the northwestern region, where whites outnumbered African-Americans. Slavery, then, was an issue, but not in the sense that it was in other border states.
Upon Virginia's secession, the Wheeling Convention, named for the town of Wheeling, and maintaining of those from the northwest area, voted to repeal secession. This condemned in what was known as the Restored Government of Virginia, which established what became known as West Virginia, and separated the two parts of Virginia.
Not surprisingly, sentiment for both the Union and Confederacy was strong in the new West Virginia. Those who joined the Federal and Confederate armies were nearly equal in numbers. Guerrilla warfare in the new state was rampant, and lasted until 1865.
The border states were often the sites of some of the bloodiest battles of the Civil War, a fact that is both ironic and understandable. The "brother against brother" situations that typified the war were never more precalent than in states where the populace was as divided among themselves as the Union and the Confederacy were.