What Civil War?

In 1861, Abraham Lincoln launched an unconstitutional war against the Southern states. During that four-year conflict, the people of the South were forced to defend their homes and families—not to mention their newly formed nation—against an invading army. They were in no way trying to overthrow the U.S. government. But regardless of the facts, that period of American history is still known as the "Civil War."

Fast forward 140 years or so. We are constantly being reminded by "conservative," "non-mainstream" media sources that the struggle between different groups of Iraqis for control of Iraq is not a civil war. Now, I'm no expert, but isn't that exactly the definition of civil war?