<P> During the American Civil War ( 1861 -- 1865 ) , the Union referred to the United States of America and specifically to the national / federal / central government of 16th President Abraham Lincoln and the 20 free states and 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 . '' </P>
<P> During the American Civil War ( 1861 -- 1865 ) , the Union referred to the United States of America and specifically to the national / federal / central government of 16th President Abraham Lincoln and the 20 free states and 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 . '' </P>
how many states were in the union during civil war
how many states were in the union during civil war
20 free states and 4 border and slave states
20 free states and 4 border and slave states