In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.
Q: During the American Civil War (1861 -- 1865), the Union referred to the United States of America and specifically to the national government of President Abraham Lincoln and the 20 free states, 4 border and slave states (some with split governments and troops sent both north and south) that supported it. The Union was opposed by 11 southern slave states (or 13, according to the Southern view and one western territory) that formed the Confederate States of America, or also known as 'the Confederacy'.
A: 
who were the union and who were the confederates