Was Delaware a Confederate stateduring the Civil War?

Answer 1

No. While the two (of the three total) Southern counties were sympathetic to the Southern cause, and the whole state was a "slave" state, it did not secede from the Union.
http://www.history.com/this-day-in-history.do?action=Article&id=2057 states the following:

Just two weeks after South Carolina became the first state to secede from the Union, the state of Delaware rejects a similar proposal.

There had been little doubt that Delaware would remain with the North. Delaware was technically a slave state, but the institution was rare by 1861. There were 20,000 blacks living there, but only 1,800 of them were slaves--Delaware was industrializing, and most of the commercial ties were with Pennsylvania. In 1790, 15 percent of Delaware's population was enslaved, but by 1850 that figure had dropped to less than three percent. In the state's largest city, Wilmington, there were only four bondsmen. Most of the slaves were concentrated in Sussex, the southernmost of the state's three counties.

After South Carolina ratified the ordinance of secession on December 20, 1860, other states considered similar proposals. Although there were some Southern sympathizers, Delaware had a Unionist governor and the legislature was dominated by Unionists. On January 3, the legislature voted overwhelmingly to remain with the United States. For the Union, Delaware's decision was only a temporary respite from the parade of seceding states. Over the next several weeks, six states joined South Carolina in seceding; four more left after the South captured Fort Sumter in April 1861.

Answer 2

Border - that is, a slave-state that did not vote Confederate.

Both sides raised regiments from Delaware, but of the four border-states, it was the smallest and the least worrisome to Lincoln.

Answer 3

Delaware was considered a border state but was technically a part of the Union.

Answer 4

No, Delaware remained in the Union. Secession was voted on but it was rejected.