They were not, as doing so would have legitimized their claim. /u/khosikulu gives a good post on why no outside government recognized the CSA here.

In effect, any nation recognizing the Confederacy as a separate nation would be making war against the Union. (Secretary of State) Seward made this quite clear ... [b]ut recognizing the Confederacy during the conflict would give the stamp of approval to the breakup of the United States.

In short, if the US had recognized the CSA as a separate country, then the civil war would have been viewed as an invasion of a neighbouring country instead of an internal rebellion.

I actually first came across this here, discussing American "wars".