how did the civil war end? who surrendered

2 answers

The South surrendered to the North. This kept the U.S. together as one nation.
http://en.wikipedia.org/wiki/List_of_civil_wars

I imagine your question was about the US Civil War, and Ms. Sue has given you good information. You should be careful in your terminology, though, because you can tell from the list linked above that there have been umpteen civil wars over the millennia.