There actually were some English Civil War battles in Maryland where the Catholics and Protestants took advantage of the opportunity to kill each other.That's kindda the point I trying to make...with a wee bit of humour.
Almost all nations have had a civil war at least once in their respective histories: the French Revolution, Russian Civil War (Red Revolution), Spanish Civil War, Communist-vs-Nationalist China, Korean War, Vietnam War, etc etc etc. It could even be argued that the US Revolutionary War was, in reality, a civil war...so the 1861-1865 conflict was actually America's second civil war.
While the vast majority of Americans will call the 1861-65 conflict THE Civil War, other nations may have different interpretations.